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Term
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Description
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10/100 BaseT
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10/100BaseT is the Ethernet standard for baseband LANs using
twisted-pair cable carrying 10/100 Mbps. 100BaseT is also
called Fast Ethernet.
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a2b
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a2b music, an online music delivery company, is owned by
AT&T. The service delivers music coded in a proprietary
format based on MPEG-2 AAC. The format includes compression
and security (copyright protection) technology.
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AAC
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MPEG Advanced Audio Coding
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AAL
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ATM Adaptation Layer. It has been adopted by the ATM Forum
for a class of service called High Speed Data Transfer. AAL
is a set of standard protocols which translate user traffic
into a size and format that can be contained in the payload
of an ATM cell (53 bytes). User traffic is returned to its
original form at the destination. This process is called segmentation
and reassembly (SAR). All AAL functions occur at the ATM end-station
rather than at the switch.
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Abbreviated Dialing
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Preprogramming of a caller's phone system or long distance
company's switch to recognize a 2- to 4-digit number as an
abbreviation for a frequently dialed phone number, and automatically
dial the whole number. Synonym: Speed Dialing.
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Access Charge
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Money collected by local phone companies for use of their
circuits to originate and terminate long distance calls.
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Access Line
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A telephone circuit which connects a customer location to
a network switching center.
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Access Network
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Portion of PSTN that connects access nodes to subscribers.
Predominantly twisted pair copper wiring.
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Access Node
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Points on edge of Access Network that concentrate individual
access lines into a smaller number of feeder lines.
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Access point (for wireless LANs)
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A wireless LAN device that transports data between a wireless
network and a wired network (infrastructure). It is a transceiver
that connects the wired LAN with wireless clients. It may
also in many cases connect to a digital (DSL or cable) modem
and enables high-speed (broadband) Internet access throughout
the home network.
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Access Router
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Interfaces a LAN to a WAN.
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Access Time
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The time a program or device takes to locate a data/information
and make it available to the computer for processing. It is
the time it takes to get data into and out of a memory device.
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Accumulator
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A logic circuit that does successive arithemetic functions
like addition or subtraction.
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ACL (Bluetooth)
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Asynchronous ConnectionLess
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Active Slave State (Bluetooth)
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Connected and actively monitoring/participating on a Piconet
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Adaptation Protocol (Bluetooth)
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Adaptation Protocol is a series of software modules that
provide backward compatibility and new APIs to the host application.
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Add-on devices
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Devices that are traditionally added to the base PC system
to increase functionality, such as audio, video, networking,
graphics, etc. Add-on devices fall into two categories: devices
built onto the system board and devices on expansion cards
added to the system through a system board connector such
as PCI.
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Address
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A number that represents a location in the memory. Usually
shown in a hexadecimal value for memory or storage.
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Adobe PostScript
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A page description language (PDL) developed by Adobe Systems
Incorporated, and used on many high-end printers.
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Adobe Type Manager
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(ATM); a font management and rasterization program which
converts Adobe Type 1 and Type 3 fonts to bitmaps for printing
or display on a computer screen. ATM is available as a program
to run in the Windows environment to allow the display of
PostScript fonts by Windows programs, and is built-in to some
other graphical user interfaces.
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ADPCM
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Adaptive Differential Pulse Code Modulation. It is a PCM
encoding technique by which analog voice samples are encoded
into high-quality digital signals. By adapting the quantizing
range to the difference between the two samples, it achieves
the same voice quality.
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ADSL
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Asymmetric Digital Subscriber Line. DSL is a method for high-speed
digital data transmission over regular phone lines. While
the wires coming into the subscriber's premises are the same
(copper-pair) wires used for regular phone service, an ADSL
circuit is much faster than a regular phone connection. This
technology supports up to 8 Mbps downstream channel and a
narrow upstream band up to 1.5 Mbps, to transmit POTS and
data to and from customer location. This powerful technology
allows a user to enjoy video-on-demand on their TV, use the
Internet for Web, email access on multiple PCs and carry on
a telephone conversation on a pair of copper wires installed
50 years ago by using ADSL technology. ADSL is a popular implementation
of DSL. The "asymmetric" in ADSL means that it transmits
data at faster speeds downstream (from the Internet to the
computer) than upstream (from the computer to the Internet).
Comes in several forms: G.Lite ADSL & G.dmt ADSL and both
forms provide always on connections without having t
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AFE
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Analog Front End
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Agent
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An Agent is any initiator/target on the PCI bus.
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Aggregate Throughput
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A measure of the theoretical maximum amount of data a network
(communications system) can carry within a time frame. It
is the total summation of all data rates of all simultaneous
transmissions possible at one instance on the system. For
example if a system could support 5 simultaneous transmissions
of 2 Mbit/sec.
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AGP
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Acronym for Accelerated Graphics Port. An industry I/O standard
which provides high-speed transfer of 3D-graphics data between
the graphics controller and the system memory.
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Aliasing
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Incorrect sampled data obtained by either not sampling fast
enough or not bandlimiting the signal prior to sampling. Can
result in artifacts inserted into the image.
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Alliance Series
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Xilinx's Place And Route (PAR) tool that works with other
3rd party EDA tools such as Synopsys, Synplicity, Cadence,
Mentor or Exemplar.
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AllianceCore
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Intelectual Property (IP) developed by 3rd party developers.
Xilinx works closely with these developers to certify and
ensure they meet quality and re-usability standards.
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ALLSTAR
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Acronym for ALLiance STARter package. A 3rd party evaluation
software package included within the Foundation ISE software.
(see Sales Partner Web or software marketing for latest information)
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ALU
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Acronym for Arithmetic Logic Unit. A logic function that
performs arithmetic computations, such as addition, multiplication,
and comparison operations. The ALU is one component of the
CPU (central processing unit).
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AM
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Amplitude Modulation. A technique in which the amplitude
(voltage level) of a carrier is varied in order to transmit
digital or analog information.
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AMA (Bluetooth)
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Active Member Address
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AMR
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Automated Meter Reading
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Analog
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A method of signal representation by an infinitely smooth
universe of numeric values (continuous waveforms). The world,
as we have experienced it, is an analog world. Any kind of
information, e.g. Sound Speech, Pictures, is transmitted in
continuous wave forms which the human senses are able to receive
and interpret. Measurements that are characterized as analog
include readings of voltage and current.
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Analog Transmission
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Signal transmission over wires or wireless medium in which
information is conveyed through the variation of some combination
of signal amplitude, frequency and phase.
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ANSI
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American National Standards Institute. Voluntary organization
composed of corporate, government, and other members that
coordinates standards-related activities, approves U.S. national
standards, and develops positions for the United States in
international standards organizations. ANSI also accredits
and implements standards developed by other organizations
for among other things, computer, communications and networking.
ANSI is a member of the IEC and the ISO.
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Antenna
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The part of a radio communications system intended to radiate
and/or collect radio frequency (RF) energy.
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API
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Application Programming Interface. It is a software interface
provided between a specialized communications program and
an end-user application. It is a set of building blocks -
routines, protocols and tools for building software applications
and enable application developers to take advantage of various
wireless networks.
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Application
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Services for applications
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Application Layer
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The layer of the OSI model concerned with application programs
such as electronic mail, database managers, and file server
software. The Application Layer is where the user applications
software lies. The Application Layer serves as the window
for the application process to access the networking environment.
This layer represents the services that directly support users
and application tasks. The Application Layer handles issues
such as: File access and transfer, Virtual terminal emulation,
Inter process communication, Electronic Mail, and Network
Management.
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Architecture
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The term architecture can refer to either hardware or software,
or to a combination of hardware and software. The architecture
of a system always defines its broad outlines, and may define
precise mechanisms as well. In general terms it describes
the design and look of a electronic component; either in hardware
or software.
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ARQ
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Automatic Repeat reQuest
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Artifact
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Any strange or undesired feature of a rendered image.
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ASIC
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Application Specific Integrated Circuit. A semi custom integrated
circuit made to do a specific function or application.
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Assembly Language
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A programming language that is once removed from a computer's
machine language. Machine languages consist entirely of numbers
and are almost impossible for humans to read and write. Assembly
languages have the same structure and set of commands as machine
languages, but they enable a programmer to use names instead
of numbers.
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Association
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Service enables establishment of wireless links between wireless
clients & APs in Infrastructure Networks.
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ASSP
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Application-Specific Standard Product. Type of high-integration
chip or chipset ASIC that is designed for a common yet specific
application.
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Asynchronous
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A mode of data transmission in which the time occurrence
of the bits within each character (or block of characters)
relates to a fixed time frame, but the start of each character
(or block of characters) is not related to this fixed time
frame. Hence the logic changes independent of the clock, and
the output can change at any time an input changes.
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Asynchronous data transfer
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Asynchronous data transfer puts the emphasis on guaranteed
delivery of data, with less emphasis on guaranteed timing.
Asynchronous transfers are targeted to a specific node with
an explicit address. They are not guaranteed a specific amount
of bandwidth on the bus. They are guaranteed a fair shot at
gaining access to the bus when asynchronous transfers are
permitted. Asynchronous transfers are acknowledged and responded
to . This allows error-checking and retransmission mechanisms
to take place.
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Asynchronous Logic
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Logic that changes independently of clock.
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ATM
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Automatic Teller Machine
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ATM
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Asynchronous Transfer Mode. A high-speed/high bandwidth,
low-delay, connection-oriented, packet-like switching and
multiplexing technique requiring -byte fixed sized cells.
This technology uses 53-byte cells (5-byte header, 48-byte
payload) to transmit different types of simultaneous data,
voice and video traffic.
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ATM Networks
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Asynchronous Transfer Mode Networks
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ATSC
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Advanced Television System Committee
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Attenuation
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The loss or weakening in signal amplitude or signal power
through a transmission line, transmission component, or signal
path over distance refers to attenuation. This is typically
measured in decibels (dB). As an example, phonelines are suitable
for home networking because there's adequate signal strength
between jacks in different rooms or on different floors.
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ATU-C (ATU-R)
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ADSL Transmission Unit, Central (or Remote). Device directly
connected to ADSL line. The Central unit is typically housed
with many others at the CO. The Remote unit is at the customer,
and can be a modem, NIC, or router.
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ATU-C DSL
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Termination at the CO (central office); also known as "DSLAM."
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ATU-R DSL
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Termination at the user side; also known as "DSL modem."
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ATV
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Advanced television (high-definition television).
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Authentication
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Process of proving client identity
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Automatic Power Down Mode
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The device can be brought into this mode by selectively controlling
the features of a design which consume large amounts of power.
The reduction in power is obtained without clearing the registers.
As a result, the register data is retained. The inputs and
outputs are not disabled and as a result, the device remains
active during this mode.
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AV
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Audio video
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B (Bearer) Channel
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A 64 kilobit-per-second (kbps) circuit switched channel used
for voice or data.
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Back Channel
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To enable interactive and Pay TV services, a direct communication
channel between the broadcaster or service provider and the
consumer is needed.Normally this "Back" or "Return channel
" is realized via the normal telephone line.
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Backplane
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System interface connecting two or more boards.
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Band-Pass Filter
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A filter that passes signals that are between an upper and
a lower frequency boundaries.
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Bandwidth
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Bandwidth is a measure of the carrying capacity (or size/width)
of a communication (or operating or transmission) channel.
This equates to the amount of data that can be transmitted
in a fixed amount of time, or it is the amount of data that
an application can process. For digital devices, the bandwidth
is usually expressed in bits per second (bps) or bytes per
second (Bps). For analog devices, the bandwidth is the difference
between the highest and lowest frequencies of a band that
can be passed by a transmission medium without undue distortion,
and can be expressed in cycles per second, or Hertz (Hz).
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Bandwidth (broadband, narrowband)
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The speed of data transmission depends on the available bandwidth
of the transmission channel. Narrow band channels provide
data transfer rates of 100 kbit/s (NA.MHz), whereas broad
band channels allow transfer of >1 Mbit/s (NA.MHz).
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Baseband
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Using entire bandwidth of a medium to carry a single signal.
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Baseband Controller (Bluetooth)
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The baseband controller is responsible for all of the digital
data processing required for radio transmission. This includes
speech coding of Synchronous Connection Oriented (SCO) data
streams, data whitening (essentially simplistic encryption
for rudimentary security), robust 128-bit encryption if requested,
packetization, and error detection and correction for both
the packet header and the payload.
An additional responsibility is the calculation of the Frequency
Hopping (FH) pattern for the radio to use. Bluetooth hops
uses frequency hopping spread spectrum transmissions that
hop 1600 times per second across 79 different 1MHz channels
in the 2.4GHz ISM band (2.402GHz - 2.480GHz). This scheme
provides excellent noise immunity and graceful signal degradation.
The Bluetooth FH pattern is algorithmically determined (i.e.calculated)
as a function of the Master device ID which is unique for
each and every Bluetooth device.
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Baud
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Byte at Unit Density. It is a measure of the speed of transmission
of data per second. It can also be measured as the number
of signal level changes per second where each signal level
contains one (or more) bits of information.
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BAV (HAVi)
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BAV is an acronym for Base AV (device).
BAV devices are simple and inexpensive devices that do not
have sufficient local resources to implement all the HAVi
APIs and protocols. BAVs therefore rely on the more powerful
FAV (Full AV) devices to install and execute their DCM.
A typical example of a BAV would be a digital still picture
camera.
BAV devices are 'HAVi aware' but need to implement only a
very small part of the HAVi protocols.
BAV devices can always be directly connected to the HAVi
network and they carry within themselves their own DCM written
in Java. So, provided that there is at least one FAV (Full
AV) in the HAVi network with sufficient resources to install
the DCM, a BAV is controllable.
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BER
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Bit Error Ratio. It is the measure of transmission quality,
thus indicating the number of incorrect bits in a given bit
stream compared to the total number of bits transmitted in
a given duration time.
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BGA
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Acronym for Ball Grid Array. A leadless, surface mounted
package with high I/O count.
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Binary
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Pertaining to a number system that has just two unique digits.
For most purposes, we use the decimal number system, which
has ten unique digits, 0 through 9. All other numbers are
then formed by combining these ten digits. Computers are based
on the binary numbering system, which consists of just two
unique numbers, 0 and 1. All operations that are possible
in the decimal system (addition, subtraction, multiplication,
division) are equally possible in the binary system.
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Bit
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Acronym for BInary digiT. The smallest unit of information
in a digital system that can either be a 1 or 0.
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Bit rate
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The rate at which a storage medium delivers a compressed
bitstream to a decoder's input.
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Bitmap
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An array of dots, normally containing an image formed by
a pattern of "white" dots and "black" dots.
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Bitmap Font
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A font in which each character is stored as an array of
dots, the pattern of which forms a letter or symbol.
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Bitmap Graphic
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An array of dots, in which the pattern of the dots forms
a picture or other non-text item such as a line.
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Bits
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Short for binary digit, the smallest unit of information
on a machine. The term was first used in 1946 by John Tukey,
a leading statistician and adviser to five presidents. A single
bit can hold only one of two values: 0 or 1. More meaningful
information is obtained by combining consecutive bits into
larger units. For example, a byte is composed of 8 consecutive
bits.
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Bitstream (Bitmap)
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The bitstream is a binary representation of an implemented
FPGA design or the designer's logic. The bit-stream is generated
by the Xilinx software tool 'BITGen' and the output file has
<.bit> file extension. It contains the configuration
information used to program an FPGA.
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Block Cipher
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TA cipher that encrypts a block of data all at once, and
then goes on to the next block.
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Block Code
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Converts a fixed length of K data bits to a fixed length
N code word, where N > K.The rate of the code is K/N.
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Block RAM
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Dedicated blocks of memory available on-chip.
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Blocked Calls
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Attempted calls that are not connected because either all
lines to the central offices are in use; or all connecting
paths through the PBX/switch are in use.
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BlockSelectRAM
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See BlockRAM
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Bluetooth
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Bluetooth is a global de facto standard for wireless connectivity.
Based on a low-cost, short-range radio link, Bluetooth cuts
the cords that used to tie up digital devices such as mobile
PCs, mobile phones and other portable devices. The Bluetooth
Special Interest Group is an industry group consisting of
leaders in the telecommunications and computing industries
that are driving development of the technology and bringing
it to market.
When two Bluetooth equipped devices come within 10 meters
range of each other, they can establish a connection together.
And because Bluetooth utilizes a radio-based link, it doesn't
require a line-of-sight connection in order to communicate.
Your laptop could send information to a printer in the next
room, or your microwave could send a message to your mobile
phone telling you that your meal is ready. Ericsson, the principal
inventor of Bluetooth, borrowed the name from Harald Bluetooth
(son of Gorm) who was the King of Denmark circa 900AD.
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Boundary Scan
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It facilitates the testing, device programming and debug
at the device, board and systems level. Also known as IEEE/ANSI
standard 1149.1.
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Bouquet
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A collection of services marketed as a single entity.
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bps
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Bits per second. Basic unit of data transmission.
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BPSK
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Binary Phase Shift Keying. Digital DSB suppressed carrier
modulation.
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BRAN
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Broadband Radio Access Network
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BRI (Basic Rate Interface)
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Basic Rate ISDN. Services targeted at home and small business
users. BRI service is delivered over a single twisted pair,
the same wiring that is used to deliver POTS. It includes
three fully duplex data channels. Two of these, referred to
as Bearer or B channels, are used to carry voice or data.
The third, the D channel, is used to communicate control information
between the central office switch and the ISDN terminal device.
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Bridge
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A bridge is a device used to connect two distinct segments
and transmit traffic between them, such as local-area networks
(LANs) or segments of the same LAN by forwarding packets across
connections at the Media Access Control (MAC is a sublayer
of the data link layer of the OSI model). The two LANs being
connected may be alike or dissimilar, i.e., from one physical
medium to another. For example, a bridge can connect an Ethernet
network with a wireless LAN network. A bridge works at the
data-link level of a network, copying a data frame from one
network to the next network along the communications path.
Bridges can make minor changes to the frame before forwarding
it(such as adding and deleting some fields from the frame
header). Unlike routers, bridges are protocol-independent
and simply forward packets without analyzing and re-routing
messages. Consequently, they're faster than routers, but also
less versatile.
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Broadband
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Sharing the bandwidth of a medium to carry more than one
signal; typically data rates above 1.5/2.0 Mbps.
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Broadband Access
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Quite simply it is a high speed (greater than 128Kbps), always
on connection to the Internet. It allows simultaneous up-Link
and down-link communication and is made possible by digital
modems. Broadband access technologies include xDSL, cable,
satellite and ISDN.
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Broadband, Broadband Communications
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Broadband refers to a communications systems in which the
medium of transmission (such as a wire or fiber-optic cable)
carries multiple messages at a time, each message is modulated
on its own carrier frequency by means of modems and transmission
speeds are at or exceed 128 Kbps. Any of several methods such
as cable, xDSL, ISDN or cable are examples of broadband technologies
for sending Internet data into the home at high-speeds.
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Broadcaster
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An organization which assembles a sequence of events or programs
to be delivered to the viewer based upon a schedule.
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Bubble Jet
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Canon's trade name for its thermal drop on demand ink jet
printer technology. The ink is heated, producing bubble that
expands and ejects the ink out of the nozzle. As the bubble
cools, the vacuum created draws fresh ink back into the nozzle.
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Built-in Font
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See resident font.
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Burst Transaction
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Any transaction consisting of more than one data phase.
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Bytes
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Abbreviation for binary term, a unit of storage capable of
holding a single character. On almost all modern computers,
a byte is equal to 8 bits.
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CA
|
Conditional Access. A system to control subscriber access
to services, programs and events e.g. Nagra, Viaccess, Irdeto,
SECA.
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Cable
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CABLE is short for cable TV (CATV) network. Internet access
is provided on the same cable as regular cable TV and is offered
by cable companies. The subscriber requires a cable modem.
Cable provides potential speeds up to 10Mbps, but the number
of users on the system affects the overall access speed.
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Cable modem
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A modem that sends and receives data through a coaxial cable
television network instead of the telephone lines. A type
of modem that connects a computer to the cable TV (CATV) network,
which in turn connects to the Internet. Once connected, cable
modem users have a continuous connection to the Internet.
Cable modems feature asymmetric transfer rates: around 36
Mbps downstream and from 200 Kbps to 2 Mbps upstream. It is
a modem in the true sense of the word that modulates and demodulates
signals and delivers Internet data to the desktop at blazing
speeds. It simply uses the increased bandwidth of the TV cable
instead of an ordinary phone line.
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Cache
|
Pronounced cash, a special high-speed storage/memory mechanism.
It can be either a reserved section of main memory or an independent
high-speed storage device. Two types of caching are commonly
used in personal computers: memory caching and disk caching.
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CAM
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Acronym for Content Addressable Memory. It finds the address
of specified data.
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CAP
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Carrierless Amplitude/Phase modulation. A two-dimensional
passband line code derived from QAM.
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Carrier
|
A long distance company which primarily uses its own transmission
facilities, as opposed to resellers which lease or buy most
or all transmission facilities from carriers. Many people
refer to any type of long distance company, whether it has
its own network or not, as a carrier, so the terrm is not
as restrictive as it used to be.
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Carrier Access Code (CAC)
|
The sequence an end user dials to obtain access to the switched
services of a carrier. Carrier Access Codes for Feature Group
D are composed of five digits, in the form 10XXX, where XXX
is the Carrier Identification Code.
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Carrier Common Line Charge (CCLC)
|
A per minute charge paid by long distance companies to local
phone companies for the use of local public switched networks
at either or both ends of a long distance call. This charge
goes to pay part of the cost of telephone poles, wires, etc.
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Carrier Identification Code (CIC)
|
The three-digit number that uniquely identifies a carrier.
The Carrier Identification Code is indicated by XXX in the
Carrier Access Code. The same code applies to an individual
carrier throughout the area served by the North American numbering
plan.
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Carrier System
|
A system for providing several communications channels over
a single path.
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Carry-chain
|
See carry logic
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Carry-logic
|
An FPGA architectural feature for efficient, high speed arithmetic
functions.
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Cartridge
|
May refer to ROM cartridge, font cartridge, emulation cartridge,
toner cartridge, toner/developer cartridge or print cartridge.
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CBC
|
Cipher Block Chaining
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CCK
|
Complimentary Code Keying
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CD
|
Compact Disc
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CDMA
|
Code Division Multiple Access. A spread-spectrum digital
cellular radio system that uses different codes to permit
and distinguish users operating simultaneously on the same
frequency. This technique is used to increase channel capacity.
Typically each user is given a different pseudo-random spreading
code. To communicate with a particular user, the sender must
select the code assigned to that user.
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CEBus
|
Consumer Electronics Bus. A communications standard for in
home networks developed by the Electronics Industry Association
(EIA) and the Consumer Electronics Manufacturers Association.
CEBus is a standard for a communication network for consumer
products in the home. CEBus is an open architecture which
explains how to make products communicate through; Power line
wires, Low voltage twisted pairs, Coax, Infrared, RF, and
Fiber optics. The CEBus based products consist of two fundamental
components - a transceiver and a micro controller. The transceiver
implements spread spectrum technology and the controller runs
the protocol. Data packets are transmitted by the transceiver
at about 10 Kilobits per second (Kbps), using spread spectrum
technology. The CEBus protocol uses a peer-to-peer communications
model so that any node on the network has access to the media
at any time.
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Cellular
|
A wireless communications network architecture which employs
"cells" or modular coverage areas, typically serviced by a
"cell site or base station" and usually provides
hand-off capability between cells for roaming devices.
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Centronics Interface
|
This 36-pin connection was designed by Centronics Corporation
and has become the preferred way to attach most printers to
a PC parallel data port.
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CFB
|
Cipher Feedback
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Character Attributes
|
A misnomer for typestyle, commonly used to refer to bold,
italic, underline and other typestyle qualifiers used with
a typeface.
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Charged Roller
|
A roller in a laser printer which imparts an electrostatic
charge to another surface. Charged rollers are used in some
small printers in place of corotrons to reduce ozone emissions.
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CHI
|
Concentration Highway Interface, a TDM scheme defined by
Lucent.
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Chip (Chipping Code)
|
A term in spread spectrum, referring to the time it takes
to transmit a bit or single symbol of a PN code (a single
element of the spreading code).
|
|
ChipScope ILA
|
Debugging tool that allows designers to see real-time signals
within an FPGA through hardware functions and software programs.
|
|
Chrominance
|
Portion of a video signal carrying color information.
|
|
Ciphertext
|
The disguised message
|
|
Circuit Switched
|
Circuit switched is a switching system in which a dedicated
physical circuit path must exist between sender and receiver
for the duration of the "call." Used in the phone company
network, circuit switching often is contrasted with contention
and token passing as a channel-access method, and with message
switching and packet switching as a switching technique.
|
|
Circuit Switching
|
A communications technology where a dedicated communications
path is established between two stations.The path consists
of dedicated channels on each physical link between the stations.The
process of establishing these dedicated paths is referred
to as signaling.
|
|
CISC
|
Pronounced sisk, and stands for Complex Instruction Set Computer.
Most personal computers, use a CISC architecture, in which
the CPU supports as many as two hundred instructions. An alternative
architecture, used by many workstations and also some personal
computers, is RISC (reduced instruction set computer), which
supports fewer instructions.
|
|
CLB
|
Acronym for Configurable Logic Block. Xilinx FPGA architecture
used to implement logic functions.
|
|
CLEC
|
Competitive Local Exchange Carrier (alternative local phone
or data company). A company that builds and operates communication
networks in metropolitan areas and provides its customers
with an alternative to the local telephone company.
|
|
Clock enable
|
Clock enable is a feature for a flip flop (memory element
- storage device) that allows efficeint use of clocks.
|
|
Clock Skew
|
See skew
|
|
Clock Speed
|
Also called clock rate, the speed at which a microprocessor
executes instructions. Every computer contains an internal
clock that regulates the rate at which instructions are executed
and synchronizes all the various computer components. The
CPU requires a fixed number of clock ticks (or clock cycles)
to execute each instruction. The faster the clock, the more
instructions the CPU can execute per second. The frequency
at which a design or system may run.
|
|
Clock-to-out (Tco)
|
Timing parameter that specifies the time it takes for a signal
to appear on the output of a flip flop or I/O after the clock.
|
|
CMTS
|
Cable Modem Termination System
|
|
CMYK
|
The Cyan Magenta Yellow Black model for standards in color
ink jet printing. These are the four basic process colors
used in conventional color printing. By overlaying or dithering
combinations of these four inks in different proportions,
a vast range of colors can be created.
|
|
CO
|
Central Office. This refers to the local telephone exchange
or the local switching center of a local telephone company
office which connects to all local loops in a given area and
where circuit switching of customer lines occurs. It is the
local telephone company switching system, where Telephone
Exchange Service customer station loops are terminated for
purposes of interconnection to each other and to trunks. The
name is historically derived from the point where operators
in an office were the switching function, connecting and disconnecting
calls manually.
|
|
CO
|
Central Office - telephone company equipment to terminate
and interconnect customer lines.
|
|
Coax, Coaxial Cable
|
A concentric, two-conductor cable in which one conductor
surrounds the other, separated by an insulator.
|
|
Coaxial Cables
|
A solid center conductor is surrounded by an insulating spacer
which in turn is surrounded by a tubular outer conductor (usually
a braid, foil or both). The entire assembly is then covered
with an insulating and protective outer layer. Coaxial cables
have a wide bandwidth and are capable of carrying many data,
voice, and video conversations simultaneously. A type of cable
used to transport high frequency signals, e.g. from the LNB
to the satellite receiver.
|
|
Code
|
A code refers to a digital bit stream with noise-like characteristics.
In spread spectrum technique, the term code refers to the
pseudo-random code used to control the modulation technique
used to spread the carrier.
|
|
Code Rate
|
This is equal to the number of information symbols percode
word divided by the total number of symbols per code word.
|
|
Code Word
|
A block of n symbols.
|
|
CODEC
|
COderDECoder. Coder and Decoder function that converts analog
signal into digital pulse-coded-modulation format for transmission
through the digital public switched network. These devices
also provide the pre- and post-filtering for optimal performance
over varying loop conditions. An assembly comprising an encoder
and a decoder in the same unit. In video, refers to compression
and decompression.
|
|
Coding Gain
|
The amount of power saved by using Reed-Solomon prior to
transmitting.
|
|
Coefficients
|
A constant that is multiplied by a variable is known as a
coefficient or a scaling variable. It is commonly used in
DSP applications.
|
|
Collisions
|
In network systems, when two nodes transmit simultaneously,
causing destruction of a data packet's information.
|
|
Common Interface
|
Describes a hard and software architecture for Conditional
Access Systems whereby the generic "host" Set-top Box is not
dedicated to one particular encryption system. Consumers use
detachable modules, which allow them to receive encrypted
services they pay subscription fee for. The interface between
host Set-top Box and module is standardized (PCMCIA-Interface)
so that the same Set-top Box can be used to handle a variety
of encryption systems.
|
|
Component video
|
The video signal separated into different pieces.See RGB,
S-Video.
|
|
Composite Black
|
The creation of black from cyan, magenta and yellow inks.
Mixing inks is not a perfect operation, and composite black
is often muddy. This is why the CMYK model is used in professional
printing. See also True Black.
|
|
Composite video
|
All components (brightness, color, synchronization, etc.)
combined into one signal.See component video.
|
|
Compression
|
In RF amplification, an amplifier is said to be "in
compression" (distorting) when the output is no longer
a linear representation of the input signal, typically at
the operational limits of the amplifier.
|
|
Compression ratio
|
The size of the original image divided by the size of the
compressed image, measuring the degree to which a compression
routine can reduce the size of a file.
|
|
Conditional Access (CA)
|
A system for scrambling and encryption signals in order to
deny access to programs for those viewers who have not paid
subscription fees for these programs. (e.g. Videoguard, Eurocrypt).
|
|
Configurable Logic Block
|
See CLB
|
|
Configuration
|
It is the process of loading design-specific bitstreams
into one or more FPGA devices to define the functional operation
of the logical blocks, their interconnections, and the chip
I/O.
|
|
Configuration Mode Control
|
SpartanXL devices have three configuration modes: Slave Serial,
Master Serial and Express Mode. These modes are selected by
the M1 and M0 pins on the device. In addition, the devices
can be configured through boundary scan logic.
|
|
Connectivity
|
The ability of a device to communicate with other devices
through a data communications medium.
|
|
Consumer devices
|
Consumer electronic devices such as digital TV, PCs, gaming
consoles, web phones, set-top boxes, printers, scanners, etc.
|
|
Contour Font
|
An alternative term for an outline font.
|
|
Control Unit
|
The part of the processor which extracts instructions from
memory and decodes and executes them, calling on the ALU when
necessary.
|
|
Controller
|
Normally an abbreviation of printer controller, the dedicated
computer in a printer which creates the image to be printed.
|
|
Convolution Sum
|
This is the summation of the products of the impulse response
and the input sequence.
|
|
Core (IP)
|
See intellectual property
|
|
CORE Generator
|
Xilinx software tool that is used to select the appropriate
IP core and customize it.
|
|
Corotron
|
A wire in the printer mechanism which carries a very high
voltage to generate an electrostatic charge on a nearby surface,
such as photoreceptor or sheet of paper. There are several
corotrons in most printers. The high voltage in corotrons
ionizes the air surrounding the corotron and generates ozone
gas as a by-product.
|
|
Correlator
|
The receiver component that demodulates a spread spectrum
signal. It is used to measure the similarity of two signals.
It is also referred to as a "de-spreader" in direct sequence
systems.
|
|
CPE
|
Customer Premises Equipment. Telecommunications equipment
that is located at the subscribers' home or business and that
could potentially belong to the customer rather than the network
operator.
|
|
CPLD
|
Complex Programmable Logic Device. Non-volatile programmable
device that is based on programmbale AND-OR structure.
|
|
CPU
|
Central Processing Unit. It is the main processing element
of a switch or microprocessor and thus is the brains of the
computer. Sometimes referred to simply as the processor or
central processor, the CPU is where most calculations take
place. In terms of computing power, the CPU is the most important
element of a computer system. Two typical components of a
CPU are: ALU and the control unit.
|
|
CRC
|
Cyclic Redundancy Check. CRC is a technique to detect and
correct errors during data transmission.
|
|
Critical path
|
Logic path that limits the performance of a design.
|
|
Cross-probing
|
Ability of different software tools or applications to talk
to each other.
|
|
CrossTalk
|
The unwanted energy (speech or tone) transferred from one
circuit to another circuit.
|
|
CRT
|
Cathode Ray Tube
|
|
Cryptanalysis
|
The art of breaking cryptosystems, and seeing through the
disguise even when you are not supposed to be able to.
|
|
Cryptographic
|
Encryption
|
|
Cryptography
|
Originally, the science and technology of keeping information
secret from unauthorized parties by using a code or a cipher.
Today, cryptography can be used for many applications that
do not involve confidentiality including digital signature,
data integrity and authentication.
|
|
Cryptology
|
The study of both cryptography and cryptanalysis.
|
|
Cryptosystem or cipher system
|
A method of disguising messages so that only certain people
can see through the disguise.
|
|
CS
|
Acronym for Chip Scale Package. It is a leadless, surface
mount, low profile package.
|
|
CSMA
|
Carrier-Sense Multiple Access
|
|
CSMA/CA
|
Carrier Sense Multiple Access / Collision Avoidance
|
|
CSMA/CD
|
Carrier Sense Multiple Access/ Collision Detect protocol.
With CSMA/CD two or more stations share a common transmission
medium. To transmit a frame, a station must wait for an idle
period on the medium when no other station is transmitting.
It then transmits the frame by broadcasting it over the medium
such that it is "heard" by all the other stations on the network.
If another device tries to send data at the same time, a "collision"
is said to occur. The transmitting station then intentionally
transmits a "jam sequence" to ensure all stations are notified
the frame transmission failed due to a collision. The station
then remains silent for a random period of time before attempting
to transmit again. This process is repeated until the frame
is eventually transmitted successfully. CSMA/CD access is
used by Ethernet (IEEE 802.3), HomePNA and wireless LANs (IEEE
802.11).
|
|
CTT
|
Acronym for Center Tap Terminated. I/O Standard for memory
bus applications.
|
|
Customer Access Line Charge (CALC)
|
The FCC-imposed monthly surcharge added to all local lines
to recover a portion of the cost of telephone poles, wires,
etc., from end users. Before deregulation, a large part of
these costs were financed by long distance users in the form
of higher charges.
|
|
Cycle Time
|
A measurement of how quickly two back-to-back accesses of
a memory chip can be made.
|
|
D (Delta) Channel
|
A 16 kbps (for BRI) or 64 kbps (for PRI) packet switched
channel used for signaling and data.
|
|
Daisy chain
|
Multiple devices that are connected in series. The output
of the first device is connected to the input of the next
device.
|
|
Data link layer
|
The OSI level that performs the assembly and transmission
of data packets (gets data packets on and off the wire), does
error detection and correction, synchronization and retransmission.
It includes the Medium Access Control (MAC) & Logical
Link Control (LLC). The LLC on the upper half, which does
the error checking The MAC on the lower half, which deals
with getting the data on and off the wire.The primary purpose
of the Data Link Layer is to provide error-free transmission
of information between two end stations "edge nodes" attached
to the same physical cable or media. This then allows the
next higher layer to assume virtually error-free transmission
over the physical link. The Data Link Layer is responsible
for packaging and placing data on the network media. It then
manages how the flow process of the bit stream takes place.
|
|
Data Width
|
Total number of bits/bytes of data that can be accessed
(read or written) simultaneously.
|
|
DAVIC
|
Digital Audio Video Council. An international group which
met for the first time in 1994, is set up to define the interfaces
and protocols necessary to support delivery of international
digital video services.
|
|
dB
|
Decibel. A logarithmic representation of magnitude relationships
commonly used in radio and sound measurement.
|
|
DBS
|
Direct Broadcasting Satellite (TV). It is an American transmission
system based on high powered Ku-band satellites (120-200 watts
per transponder). The signals can be received using a small
18 inch dish. Currently there are four DBS-Services in peration
in the US (Primestar, DirecTV/USSB and EchoStar).
|
|
DBS
|
Direct-broadcast satellite (TV).
|
|
DCF
|
Distributed Coordination Function
|
|
DCM (HAVi)
|
Device Control Modules.
A Device Control Module (DCM) is a Software Element that
is installed and executed on a HAVi device that provides control
over device-specific functionality, (such as a VCR or a camera)
via the HAVi-defined APIs (such as the "PLAY" API of a VCR).
DCMs are installable Software Elements, which means that their
presence depends on which devices or functionality is actually
present in a particular HAVi network.
In principle there can be multiple DCMs for one particular
device present in a HAVi network. When a device is inserted
or powered up in the network, all IAVs and FAVs will check
to determine if they have a DCM for that device, and will
then negotiate with each other as to which DCM will be installed
for the device, and on which IAV or FAV it will be installed.
Only one DCM can be installed at any time for each particular
device. This selection and installation process is controlled
by the DCMs on the IAVs and FAVs, however, HAVi offers several
user definable preferences setting.
|
|
DCT
|
Discrete Cosine Transform. This is the Cosine ofthe infinite
Fourier series.
|
|
DDR
|
Double Data Rate. This memory transfers data on both edges
of the clock.
|
|
DDR RAM
|
Acronym for Dual Data Rate. Type of RAM that runs twice as
fast as traditional RAMs. DDR RAM is written to, or read from
on both clock edges.
|
|
Decoder
|
A device that restores a signal to its original form after
it has been encoded. It is the block responsible for stripping
the extra bits appended by the Encoder to the digital data.
|
|
Decoding
|
A process in which the original coded information is reconstructed.
|
|
Decryption
|
A procedure to convert ciphertext back into plaintext.
|
|
DECT
|
Digital Enhanced Cordless Telecommunications
|
|
Delta Modulation (DM)
|
A variant of pulse code modulation whereby a code representing
the difference between the amplitude of a sample and the amplitude
of the previous one is sent. Operates well in the presence
of noise, but requires a wide frequency band.
|
|
Demodulate
|
To convert a modulated signal back to an unmodulated "baseband"
signal.
|
|
Demodulation
|
Opposite of modulation; the process of retrieving data from
a modulated carrier wave. Conversion of analog carrier signal
to digital information.
|
|
Demodulator
|
A device that extracts digital information from transmitted
carrier waves.
|
|
DES
|
The Data Encryption Standard. An encryption standard issued
by the National Bureau of Standards, it was adopted by the
U.S. government in 1977, as the federal standard for the encryption
of commercial and sensitive-yet-unclassified government computer
data and is defined in FIPS 46 (1977). The DES is the algorithm
in which a 64-bit block of plaintext is transformed (encrypted/enciphered)
into a 64-bit ciphertext under the control of a 56-bit internal
key, by means of permutation and substitution.
|
|
Design Reuse
|
Establishing proven designs into intellectual property (IP)
for use in future designs.
|
|
De-spreading
|
The process used by a correlator to recover narrowband information
from a spread spectrum signal.
|
|
Developer
|
The mechanism and magnetic powder used to transfer toner
from the toner hopper onto the photoreceptor.
|
|
DFF
|
Acronym for Data Flip Flop. A basic logic function that stores
the input value of a signal when triggered by the clock input.
|
|
DFPQ
|
Distributed fair priority queuing
|
|
DHCP
|
Dynamic Host Configuration Protocol. A TCP/IP protocol that
enables a network connected to the Internet to assign a temporary
IP address to a host automatically when the host connects
to the network.
|
|
Dial Tone
|
A tone indicating that automatic switching equipment is
ready to receive signals.
|
|
Diffuse Dither
|
A method for printing continuous-tone images on laser printers
in which the grayscale information is represented by randomly
located printer dots. Diffuse dithers do not photocopy well
because of the small, random, dot location in the image.
|
|
Digital Certificates
|
A virtual security document which ensures the association
between the user's public key and the user's identity and
security privileges.
|
|
Digital Compression
|
A way of reducing the number of bits in a digital signal
by using mathematical algorithms to eliminate redundant information,
thereby reducing the space the signal occupies when being
transmitted or recorded.
|
|
Digital modem
|
A system component which allows modem users to communicate
over digital access/communications channels. They work by
converting the PCM-encoded digital data streams sent by analogue
modem users into their original analogue waveform.
|
|
Digital signal
|
A signal that is composed of two energy levels (on (1) and
off (0)). Digital signals are used by computers to transmit
data. The pattern of the level changes represents individual
bits of information.
|
|
Digital Signature
|
A method of signing electronic documents using public key
encryption that certifies that the document was originated
or "signed" by a specific person or organization. It can also
be used to verify the integrity of the document.
|
|
Direct Form
|
A filter implementation that only has delays, summations
and multiplication but no feedback
|
|
Dish
|
The dish collects, reflects and focuses the satellite signal
into the LNB.
|
|
Distributed Arithmetic
|
A method which breaks down DSP algorithms to its basic components
of ANDs and ORs, allowing from serial to fully parallel realizations
in the Xilinx FPGA architecture.
|
|
Distributed RAM
|
Xilinx term for implementation of RAM within a CLB.
|
|
Dithering
|
A halftoning method where several dots of the primary colors
are printed in various patterns to give the impression of
a larger color spectrum.
|
|
DLC
|
Digital Loop Carrier. Equipment located in street-side cabinets
or on telephone poles that collects copper telephone circuits
onto a fiber optic connection to the CO. Some DLCs are able
to support DSL lines for ILEC. CLECs cannot (usually) deploy
DSL to customers hosted on DLCs.
|
|
DLL
|
Acronym for Delay Locked Loop. A digital circuit used to
perform clock management functions on and off-chip.
|
|
DLP
|
Digital light processor
|
|
DMA
|
Acronym for Direct Memory Access. Logic function that allows
the memory to be accessed directly by a peripheral.
|
|
DMT
|
Discrete Multi-Tone. Modulation scheme in which available
bandwidth is divided into sub-channels (256 for downstream),
maximizing the use of the clearer channels.Recently selected
by ANSI and ETSI over CAP for ADSL standard. DMT is a form
of Frequency Division Multiplexing.
|
|
DNS
|
Domain Name System - The distributed name/address mechanism
used in the Internet. The DNS is used for mapping host names
onto their network addresses.
|
|
DOCSIS
|
Data Over Cable Service Interface Specification. The dominating
cable modem spec that defines the technical specs for both
the cable modem and the CMTS.
|
|
Dot
|
A single point written by a laser, or a single point in
a bitmap.
|
|
Dot Matrix
|
A type of printer, also known as serial dot matrix, that
uses one or two columns of dot hammers to form images out
of dots. The more dot hammers used, the higher the resolution
of the printed image.
|
|
Doubleword
|
32 bits, most often known as "DWORD".
|
|
Down-converter
|
A device that reduces the high frequency signal to a lower,
intermediate range.There are three types of down-conversion:
signal, dual and block.
|
|
Down-link
|
Term used to describe the re-transmitting of signals from
a satellite, back to Earth.
|
|
Download
|
The download function enables service providers to update
the system software of their Set-top Boxes via their transmission
channels.
|
|
Download Audio
|
Downloading, which involves transferring the entire file
to your computer before any part of it is accessible, offers
better quality since the data rate of the compressed stream
does not have to less than the data rate of the internet connection.
MP3 audio for example, is targeted at data rates from 64 to
128 Kbps. The goal of these formats is to provide near CD
quality audio.
|
|
Downloaded Font
|
A font which is stored in a computer, and sent to the printer
via the communications interface when required, to be stored
in the printer. Normally downloaded fonts are held in RAM
on the printer, and are lost when the printer is switched
off. Some printers are able to hold downloaded fonts on hard
disk to prevent loss when the printer is switched off.
|
|
Downstream
|
Data recieved by the modem from the Internet.
|
|
DPI
|
Dots Per Inch: a unit of measure used to describe the resolution
of images produced by printers or other output devices. The
printed dots from a 600 dpi printer are far smaller than the
dots created by a 300 dpi printer. As a result, the output
is smoother and more detailed, while dithering patterns will
deliver more realistic colors.
|
|
DPSK
|
Differential Phase Shift Keying. A simplified BPSK where
only data transitions are transmitted.
|
|
DRAM
|
Dynamic Random Access Memory. Memory that consists of small
capacitors for each bit of memory. Since capacitors do not
hold a charge indefinitely, DRAM must be constantly refreshed
to avoid losing its contents. Also, the process of reading
the contents of the memory are destructive, meaning extra
time must be spent restoring the contents of memory addresses
which are accessed, so DRAM is slower than SDRAM.
|
|
DRAM
|
Acronym for Dynamic Random Access Memory. Type of memory
where any location may be read from or written to. Data needs
to be continually refreshed.
|
|
Drum
|
A common term for a cylindrical photoreceptor.
|
|
DSL
|
Digital Subscriber Line. Local digital network loop, typically
sends high-speed data over standard phone lines. A family
of related "broadband over phone wire" technologies, used
to provide a continuous, high-speed connection directly to
an Internet Service Provider (ISP). It refers to the variety
of different types of Digital Subscriber Line protocols -
high-speed data transmission protocols that are compatible
with regular copper telephone wire.
|
|
DSL modem
|
A type of modem that connects a computer to a DSL network,
which in turn connects to the Internet providing users with
a continuous, high-speed connection to the Internet.
|
|
DSLAM
|
Digital Subscriber Local Access Multiplexer. This aggregates
multiple DSL connections onto fiber and delivers them to an
Access Switch. Takes many ADSL lines (ATU-C units) and concentrates
them, typically to a single ATM line, typically at the CO.
|
|
DSP
|
Digital Signal Processor. A specialized microprocessor which
contains hardware features specifically tailored to the processing
of signals and hence provides flexible processing of a continuous
stream of information.
|
|
DSS
|
Digital Satellite System
|
|
DSSS
|
Direct Sequence Spread Spectrum. A spread spectrum technique
where a pseudo-random code directly phase modulates a carrier,
and hence spreads its signal continuously over a wide frequency
band. DSSS generates a redundant bit pattern for each bit
to be transmitted. This bit pattern is called a chip (or chipping
code). The longer the chip, the greater the probability that
the original data can be recovered (and, of course, the more
bandwidth required). Even if one or more bits in the chip
are damaged during transmission, statistical techniques embedded
in the radio can recover the original data without the need
for retransmission. To the receiver, DSSS appears as low-power
wideband noise spectrum and is rejected (ignored) by most
narrowband receivers. The signal is despread by correlating
with a pseudo-random code identical to and in synchronization
with the code used to spread the carrier at the transmitter.
This modulation technique increases the bandwidth of the transmission.
|
|
DSTB
|
Digital Set-top Box
|
|
DTH
|
Direct-To-Home. Used to denote satellite TV signals received
by a household via an individual dish installation.
|
|
DTV
|
Digital television.
|
|
Dual port RAM
|
RAM with two independent ports, each capable of being read
and/or written simultaneously and independent of the other
port. Xilinx refers to this functionality as True DualPort
RAMTM.
|
|
Dual Tone Multi-Frequency (DTMF)
|
Also known as Touch-Tone.A type of signaling which emits
two distinct frequencies for each indicated digit.
|
|
DVB
|
Digital Video Broadcasting. This group was created to establish
a technical framework for the introduction of digital broadcasting
systems to suit the whole range of delivery mechanisms, including
cable, satellite, terrestrial and MMDS. DVB has already developed
a coherent set of methods to bring digital television to home.
|
|
DVB-C
|
Signals via Cable.
|
|
DVB-S
|
Signals via Satellite.
|
|
DVB-T
|
Signals via Terrestrial.
|
|
D-VCR
|
Digital VCR
|
|
DVD
|
Digital Video / Versatile Disk. DVD Technology provides storage
capacity that is about 6-7 times greater than that of CD technology
with the same aerial space. It provides multiple languages
on movies, with multiple language subtitles. A beam of laser
light touches the disc and data portion of a DVD disc is never
touched by a mechanical part when played eliminating wear
characteristics on the disc. The superior audio and video
quality, interactivity and distribution control incorporated
in this new medium has revolutionized video distribution.
It takes advantage of MPEG-2 technology.
|
|
DVD-A
|
Digital Video Disk - Audio. It is a new DVD format providing
multi-channel audio in a loss-less format. It is being positioned
as a replacement for the CD.
|
|
DVI
|
Digital Video Interface
|
|
DVR
|
Digital Video Recorder. It is a product that uses local storage
to enable the user controlled storage and playback of live
digital video streams on a real-time basis. The functionality
includes the ability to simultaneous record & playback
of separate video streams or different portions of the same
stream in real time.
|
|
Dye-Sublimation
|
A specialist print technology used for demanding graphic
arts and photographic applications that require continuous
tone output.
|
|
Dynamic Current
|
It is the amount of current the device needs when it is
active. The dynamic current is mainly due to switching of
internal nodes, loading on the outputs and external clocks.
|
|
Dynamic detection, auto sense
|
The process by which a system can detect that a new device
has been added or removed from the PC. This process allows
the operating system and applications to immediately begin
using the added devices or stop using the removed devices
without rebooting the system.
|
|
EBU
|
Abbreviation for European Broadcasting Union.
|
|
ECB
|
Electronic Codebook
|
|
ECG
|
(or EKG) ElectroCardioGraphy. It is used in heartbeat measurement.
|
|
Echo
|
A signal that has been reflected or otherwise returned with
sufficient magnitude and delay to be perceived by the speaker.
|
|
ECM
|
Entitlement Control Messages are private Conditional Access
information which maintain the ordered authorization.
|
|
EDA
|
Acronym for Electronic Design Automation. Software design
tools, like synthesis, schematic capture, and simulation.
|
|
Edge Enhancement
|
A generic term for the edge-smoothing technique which reduce
the jagged appearance of angled lines on laser printers, as
used in HP's Resolution Enhancement Technology, and copied
by many other printer manufacturers.
|
|
EDIF
|
Acronym for Electronic Design Interchange Format. An industry-standard
netlist format used when passing information between different
software tools.
|
|
EDO RAM
|
Acronym for Extended Data Out DRAM. Type of DRAM that is
faster than conventional DRAM.
|
|
EEG
|
ElectroEncephaloGram. It is used in brain wave measurements.
|
|
EEPROM
|
Electrically Erasable Programmable Read Only Memory. It is
the memory that can be programmed and erased electrically.
|
|
EIT
|
Abbreviation for Event Information Table.
|
|
Electronic Commerce
|
The exchange of goods, services, and fiduciary information
or instruments via distributed computer and communications
networks.
|
|
Electronic Gaming Devices or Gaming Consoles
|
Videogame consoles are consumer devices / information appliances
that deliver electronic games-based entertainment for household
consumption. These usually feature proprietary hardware designs
and software OS (operating systems). They rely primarily on
AC power as primary energy source & must be plugged into
an external video display such as a TV and can also provide
Internet & email access.
|
|
Email terminals
|
Standalone, non-portable, consumer-oriented devices that
are dedicated for accessing email without web browsing capabilities.
These do not provide Web browsers or additional applications.
It includes keyboard, small LCD screen, some soft function
keys.
|
|
Embedded controller
|
The class of microcontrollers used to support OEM-specific
implementations in mobile, networking and consumer environments.
The embedded controller performs complex low-level functions
through a simple interface to the host microprocessor(s).
|
|
embedded memory
|
Dedictated memory function that has been implemented within
an FPGA device.
|
|
Embedded Microcontroller
|
Microcontrollers are sometimes called embedded microcontrollers,
which means that they are part of an embedded system -- that
is, one part of a larger device or system.
|
|
EMI, RFI
|
Electro Magnetic Interference/Radio Frequency Interference.
Broad spectrum noise or interfering signals.
|
|
EMM
|
Entitlement Management Messages are private Conditional Access
information which specify the authorization levels or the
services of specific decoders. They may be addressed to an
individual decoder or groups of decoders.
|
|
Emulation
|
A generic term for a printer language. Most printers mimic
or "emulate" the behavior of the market-leading models of
printer by copying their printer language.
|
|
Encoder
|
A device that encodes/encrypts the signal before transmission.
The block responsible for appending extra bits to the digital
data before transmitting.
|
|
Encoding
|
A process in which information is transformed into an equivalent
set of values by following a known, predefined mathematical
rule or algorithm.
|
|
Encryption
|
The technique of applying a specific algorithm to data in
order to alter/encrypt the data's appearance and prevent other
devices from reading information. Decryption applies the algorithm
in reverse to restore the data to its original form. This
process modifies a bit stream so that it appears random. Encryption
is used for security purposes. The sender and receiver must
both employ the same encryption method.
|
|
Encryption Algorithm
|
The mathematical method by which an encryption key is combined
with plaintext to form encrypted or ciphertext and to return
ciphertext to its original plaintext form.
|
|
Energy Star
|
Dept. of Energy low power product classification typically
used for appliance and office equipment.
|
|
Engine
|
Normally an abbreviation of printer engine, the mechanism
which "writes" a bitmap onto paper.
|
|
EOF
|
End of Frame
|
|
EPAC
|
Enhanced Perceptual Audio Coder. Codec was developed by Lucent
Technologies and originally created at Bell Labs. The technology
compresses audio at a rate of 1:11.
|
|
EPG
|
A software that enables viewers to navigate easily amongst
the large number of channels provided by digital technology
in order to select the service they desire.
|
|
EPROM
|
Acronym for Electrically Programmable Read Only Memory. It
is programmed or erased using a ultraviolet source.
|
|
Error control
|
The error control is responsible for detection of transmission
errors and, where appropriate, for the retransmissions.
|
|
Error Correction Mode
|
Due to the high compression factors used in MPEG decoding
of digital signals, Error Correction Modes become necessary
to avoid any significant loss of bit information during signal
transmission. Commonly applied are Reed-Solomon Codes. The
efficiency of error correction modes are defined by the so
called bit error rate (BER), which gives the quotient received
bits to the total number of transmitted bits in a specified
time period.
|
|
Error Polynomial
|
A polynomial used in one of the steps during decoding.
|
|
Escape Code
|
A special control character used by computers and printers,
character number 27 decimal, 1B hexa-decimal in the standard
ASCII character set.
|
|
Escape Code Language
|
A printer language in which each command is preceded by
a special character, normally the escape code, to signify
that what follows is a command rather than data.
|
|
Escape Sequence
|
A sequence of characters which form a command to be obeyed
by the printer, preceded by the escape code and ended with
a termination character.
|
|
Ethernet
|
10 Mbps LAN protocol.
|
|
Ethernet address
|
An Ethernet address is a six-part hexadecimal number in which
a colon separates each part (for example, 8:0:20:1:2f:0).
This number identifies the Ethernet board installed in a PC
and is used to identify the PC as a member of the network.
|
|
Ethernet, IEEE 802.3
|
An international networking IEEE local area network (LAN)
standard, IEEE 802.3, defines the transmission of data using
a bus topology and CSMA/CD, over copper wire at a rate of
10, 100, 1000 Mbps and beyond. Although IEEE 802.3 is technically
not Ethernet, the name is commonly used. This LAN protocol
was developed by Xerox Corporation in cooperation with DEC
and Intel in 1976. The Ethernet specification served as the
basis for the IEEE 802.3 standard, which specifies the physical
and lower software layers. Ethernet, which is one of the most
widely implemented LAN standards, is a type of wired network
that supports high speed communications among devices over
a coaxial cable. It uses the CSMA/CD access method to handle
simultaneous demands. A newer version of Ethernet, called
100Base-T (or Fast Ethernet), supports data transfer rates
of 100 Mbps. And the newest version, Gigabit Ethernet supports
data rates of 1 gigabit (1,000 megabits) per second.
|
|
ETS
|
European Telecommunication Standard.
|
|
ETSI
|
European Telecommunications Standards Institute. The pan-European
communications regulatory standards board.
|
|
Euclid
|
A 3rd -4th century (ca. 300) BC Greek mathematician whose
work served as the basis for modern geometry.
|
|
Evariste Galois
|
Famous for his contributions to group theory, by producing
a method of determining when a general equation could be solved
by radicals.
|
|
Event
|
A grouping of elementary broadcast data streams with a defined
start and end time belonging to a common service, e.g. first
half of a football match, News Flash, a talk show.
|
|
Event Manager (HAVi)
|
One of the Software Elements that provide certain functionality.
In addition to the Event Manger, the Software Elements that
are needed for interoperability between HAVi devices are the
Messaging System, Registry, Resource Manager, Stream Manager,
DCM.
|
|
Extension point
|
A base-station two-radio transceiver that bridges the gap
between a wireless client and an access point or between a
wireless client and another extension point.
|
|
Face-Down
|
Refers to an output tray on a printer in which pages are
delivered with the readable side facing down. As each sheet
is placed on top of the last, multi-page documents delivered
to a face-down tray are normally in the correct page order.
|
|
Face-Up
|
Refers to an output tray on a printer in which pages are
delivered with the readable side upwards. As each sheet is
placed on top of the last, multi-page documents delivered
to a face-up tray are normally in reverse page order.
|
|
Facsimile (fax)
|
The transmission of pictures, maps or other documents via
communications circuits using a device which scans the original
document, transforms the image into coded signals and reproduces
the original document at a distant point.
|
|
Fast Ethernet
|
An extension of the Ethernet IEEE standard, IEEE 802.3u,
that defines the transmission of data over copper wire or
fiber optic cable at a rate of 100 Mbps.
|
|
FAV (HAVi)
|
FAV is an acronym for Full AV device. This would be a device,
such as a set-top box, that is designed to have Java applications
installed on it, thereby adding specific functionality to
it.
|
|
FCC
|
Federal Communications Commission. A board of commissioners,
appointed by the President, having the power to regulate wire
and radio telecommunications in the United States. he government
agency established by the Communications Act of 1934 which
regulates the interstate communications industry.
|
|
FCS
|
Frame Check Sequence
|
|
FDMA
|
Frequency Division Multiple Access. A digital radio technology
that divides the available spectrum into separate radio channels.
Generally used in conjunction with Time Division Multiple
Access (TDMA) or Code Division Multiple Access (CDMA).
|
|
Feathering
|
A term used when describing printed text quality. Feathering
occurs when deposited ink follows the contours of the paper.
Depending on the viscosity of the ink, the rougher the grain
of the paper the more pronounced the feathering will be.
|
|
FEC
|
Forward Error Correction. Correction to acertain extent,
of faulty bits in the received signal.
|
|
FEC
|
Forward Error Correction,a methodology that useserror correction
coding to transmission. This is the opposite of ARQ (automatic
repeat request) which uses retransmission of data.
|
|
FFT
|
Acronym for Fast Fourier Transform. Converts analog waveforms
into a form that can be easily analyzed for DSP applications.
|
|
FG
|
Acronym for Fine pitch ball Grid array package. A leadless,
surface mounted package that is over 50% smaller than traditional
BGA for similar pin counts.
|
|
FHSS
|
Frequency Hopping Spread Spectrum. A spread spectrum modulation
technique where the transmitter frequency hops from channel
to channel in a predetermined but pseudo-random manner. The
signal is de-hopped at the receiver by a frequency synthesizer
controlled by a pseudo-random sequence generator synchronized
to the transmitter's pseudo-random generator. Quite simply,
frequency hopping is a type of radio communications in which
the transmitter and receiver hops in synchronization from
one frequency to another according to a prearranged pattern.
|
|
Fiber Optic Cables
|
Fiber optic cabling is constructed of three concentric layers:
The "core" is the central region of an optical fiber through
which light is transmitted.
The "cladding" is the material in the middle layer. It has
a lower index of refraction than the core which serves to
confine the light to the core. An outer "protective layer",
or "buffer", serves to protect the core and cladding from
damage.
|
|
Field
|
The set of alternating lines in an interlaced video frame.An
interlaced frame consists of two fields -- a top field and
a bottom field.A field is one-half of a complete television
scanning cycle (1/60 of a second in NTSC; 1/50 of a second
in PAL/SECAM). When interlaced, two fields combine to make
one video frame.
|
|
FIFO
|
Acronym for First In First Out. Type of memory that reads
out data in the order received.
|
|
Filter
|
A device used to block or reduce signals at certain frequencies
while allowing others to pass through.
|
|
FIPS
|
Federal Information Processing Standards
|
|
FIR Filter
|
Acronym for Finite Impulse Response. IP used in DSP applications
used to filter out different frequencies.
|
|
FIR Filter Generator
|
A Xilinx tool that helps designers define and design FIR
filters.
|
|
Firewall
|
Hardware or software that restricts traffic to a private
network from an unsecured network and helps isolate LAN segments
from each other to protect data resources and help manage
traffic.
|
|
FireWire
|
Standard high-speed serial bus.Supports up to 400 Mbps today,
going to 3200 Mbps, and plug-and-play.
|
|
First Print Out Time
|
The time taken between a printer receiving the data for the
first page of a print job, and delivering the page to the
output tray. Most printers do not start printing immediately
the data is received, but need a few seconds in which to assimilate
the data, setup the page formatting, and start the motors
which drive the paper path.
|
|
Flash Memory
|
Flash memory is a non-volatile memory that can be programmed
and erased electrically. FLASH is similar to EEPROM technology
but is smaller and newer. It is used for permanent data storing.
|
|
Flip Flop
|
A basic logic function that stores the input value of a signal
when triggered by the clock input.
|
|
Floorplanner
|
Graphical tool that a designer uses to place logic.
|
|
FM
|
Frequency Modulation. An analog modulation technique whereby
the frequency of a carrier is varied to encode information.
|
|
Fmax
|
The maximum frequency at which you can operate a logic function
within the device.
|
|
Font
|
A collection of characters in a particular typeface, typestyle,
and character set. A bitmap font is normally also defined
by size and orientation.
|
|
Font Cache
|
An area of RAM in a printer which is used for the temporary
storage of bitmap fonts which have either been read from hard
disk, or created from outline fonts.
|
|
Footprint
|
The geographic area toward which a satellite directs its
signal. Within the footprint of a satellite, the reception
of the satellite signals with high quality is possible, using
a dish of specified size.
|
|
Foundation
|
A complete ready to use Xilinx software design environment.
|
|
Foundation ISE
|
A complete ready to use enhanced Xilinx software design environment
targeted for HDL designers.
|
|
Four Wire Circuits
|
Circuits which use two separate one-way transmission paths
of two wires each, as opposed to regular local lines which
usually only have two wires to carry conversations in both
directions.One set of wires carries conversation in one direction,
the other in the opposite direction.
|
|
Fourier
|
One of the great mathematicians whose theory states that
all waveforms can be represented by an infinite summation
of Sines and Cosines.
|
|
FPD
|
Flat Panel Displays
|
|
FPGA
|
Field Programmable Gate Array. Xilinx Field Programmable
Gate Arrays (FPGA) are SRAM based that use LUTs to generate
logic.
|
|
FPM RAM
|
Acronym for Fast Page Mode. Type of DRAM that allows faster
access to data in the same row or page.
|
|
Frame
|
In a data communications context this term refers to a variable
length grouping of digital data transmitted between end stations.These
frames include a header containing addressing and control
information.In a telecommunications context, a frame is pattern
appearing regularly, typically every 125 microseconds, in
a transmitted data stream that is used to define the structure
of the transmitted data and to carry control information.
A video frame consists of two interlaced fields of either
525 lines (NTSC) or 625 lines (PAL/SECAM), running at 30 frames
per second (NTSC) or 25 fps (PAL/SECAM). Film runs at 24 fps.
|
|
Frame grabber
|
A device which interfaces between a camera and a computer,
and captures a frame of video information sampled into a memory.
|
|
Frame rate
|
The speed at which video frames are scanned or displayed
-- 30 frames a second for NTSC, 25 frames per second for PAL/SECAM.
|
|
Frequency
|
It is the number of clock cycles occuring per second, is
denoted by Hertz (Hz). The unit of measurmenet is Hertz, where
1Hertz = 1 cycle/second.
|
|
FSK
|
Frequency Shift Keying. A modulation scheme for data communications
using a limited number of discrete frequencies to convey binary
information.
|
|
FTP
|
The File Transfer protocol (FTP) provides a way to move data
efficiently from one machine to another.
|
|
Full Custom
|
Device technology where all parameters (transistor size,
interconnect, etc.) can be completely user defined.
|
|
Full-Duplex Ethernet MAC
|
Full-Duplex is another mode of operation of Ethernet MAC
(Based on IEEE 802.3X) . Full-Duplex bypasses the CSMA/CD
protocol. Full-duplex mode allows two stations to simultaneously
exchange data over a point to point link that provides independent
transmit and receive paths. Since each station can simultaneously
transmit and receive data, the aggregate throughput of the
link is effectively doubled. A 10 Mb/s station operating in
full-duplex mode provides a maximum bandwidth of 20 Mb/s.
A full-duplex 100 Mb/s station provides 200 Mb/s of bandwidth.
|
|
Fuser
|
The mechanism in a laser printer which binds the toner to
the paper. Most fusers use hot rollers and fuse the toner
into the paper using heat and pressure, but a few printers
have radiant fusers which fuse using heat alone.
|
|
Fuser Oil
|
A temperature resistant oil used on fuser rollers to prevent
toner adhering to the surface of the rollers. On small printers
the fuser oil is normally contained in the fuser cleaning
pad.
|
|
FZP
|
Fast Zero Power
|
|
G.dmt
|
Splitter-based ADSL
|
|
G.Lite (G.922.2)
|
Universal DSL, also called "splitterless DSL." A version
of ADSL technology that does not require a POTS splitter to
be installed in the customer's home. A POTS splitter separates
voice from data transmission for simultaneous telephone and
data access use. G.lite, a lightweight version of ADSL l supports
downstream data rates of up to 1.5 Mbps and upstream data
rates of up to 512 Kbps.
|
|
G2
|
G2 is the name of the RealNetworks most recent audio/video
CODEC technology. The G2 includes several features targeted
specifically at streaming media applications including synchronization
with other media types such as video and graphics, and the
ability to handle data loss. According to RealAudio, the G2
Music Codec can handle packet loss up to 10-15% with minimal
reduction of audio quality.
|
|
Galois Theory
|
A branch of mathematics dealing with the general solution
of equations.
|
|
Gate Array
|
Simple type of ASIC used in creating small density semi-custom
designs by interconnecting fixed blocks of logic.
|
|
GDI
|
Graphical Device Interface: the native graphical language
of Windows. A GDI-compliant printer will print exactly what
is displayed on a Windows screen without having to transpose
it into a printer language. All the processing happens on
the PC. This helps reduce the price of the printer, since
image processing circuitry isn't needed.
|
|
Geostationary
|
Fixed orbit, approximately 36.000 km above the Earth´s equator.
Satellites parked in this orbit travel at the same speed as
the rotation of the Earth.
|
|
GHz
|
Gigahertz: A billion hertz.
|
|
Gibb's Phenomenon
|
A phenomenon that is observed when a rectangular pulse is
approximated by too few numbers of waveforms resulting in
a smudged nonrectangular version of the pulse.
|
|
Gigabit
|
One billion bit
|
|
Glitch
|
A situation where the outputs of a source device go active
while the inputs of a target device are receptive to signal
transitions. Here, it is possible for the outputs of a source
device to go from a high impedance state to High or Low logic
level, to cross the switching threshold of the inputs to the
target device thereby causing a false transition.
|
|
GMSK
|
Gaussian Minimum Shift Keying
|
|
GPSI
|
General Purpose Serial Interface
|
|
Gray Scale
|
Technique where shades of gray are synthesized using patterns
of black and white dots.
|
|
Ground Bounce
|
Noise on ground-plane causing false data at the device pins.
|
|
GSM
|
Global System for Mobile Communications
|
|
GTL
|
Acronym for Gunning Transceiver Logic. It is a high speed,
low power backplane standard.
|
|
GUI
|
Acronym for Graphical User Interface. A software interface
that is Windows based.
|
|
H x V
|
Aspect ratio in horizontal (H) and vertical (V) dimensions.
|
|
H.323
|
A standard approved by the International Telecommunication
Union (ITU) that defines how audiovisual conferencing data
is transmitted across networks. As an example, in theory,
H.323 should enable users to participate in the same conference
even though they are using different videoconferencing applications.
|
|
H2GF
|
HiperLAN2 Global Forum
|
|
Half-Duplex Ethernet MAC
|
Is the traditional form of Ethernet that uses the CSMA/CD
protocol. With CSMA/CD two or more stations share a common
transmission medium. To transmit a frame, a station must wait
for an idle period on the medium when no other station is
transmitting. It then transmits the frame by broadcasting
it over the medium such that it is "heard" by all the other
stations on the network. If another device tries to send data
at the same time, a "collision" is said to occur. The transmitting
station then intentionally transmits a "jam sequence" to ensure
all stations are notified the frame transmission failed due
to a collision. The station then remains silent for a random
period of time before attempting to transmit again. This process
is repeated until the frame is eventually transmitted successfully.
|
|
Halftone
|
Different-sized black dots produced by turning particular
dots on and off during printing, either on a laser printer,
an image setter, or a printing press. The dots repeat in a
regular pattern, creating the illusion of continuous tone.
Color ink jets use their process colors in a similar scheme.
Other colors are produced by laying down patterns of the process
color dots, varying the pattern and ratio of each color. Halftone
dots are not the same as printer dots.
|
|
Hamming Codes
|
These are the first class of linear binary codes used for
error correction in long-distance telephony.
|
|
Handheld gaming devices
|
Consumer devices used primarily for mobile electronic games
mobile. These rely on DC power as the primary energy source
and include an embedded video display, such as an LCD.
|
|
Hand-off
|
The process that occurs when a mobile user travels from one
cell (terminating communications) to another cell (initiating
communications) in a cellular network. With the exception
of CDMA networks, hand-offs normally involve switching from
one pair of frequency to another. Hand-off typically describes
the ability of a wireless network to pass the network connection
of a roaming device from one connection point to another,
without dropping the network connection.
|
|
Handover
|
The procedures by which an mobile terminal, due to its own
movement and/or due to changes in the radio environment not
caused by own movement, replaces the current association and
all established connections the mobile terminal has with one
access point to another access point.
|
|
HAVi
|
Home Audio/Video interoperability
|
|
HAVi organization
|
The HAVi Organization is a not-for-profit association of
leading consumer electronics, software, semi conductor and
computer manufacturers who have joined together to promote
a network architecture for Home Audio Video Interoperability.
|
|
HAVi spec
|
The HAVi specification is a consumer electronics (CE) industry
standard that will ensure that digital audio and video devices
that conform to this standard, regardless of manufacturer,
will have complete interoperability when connected via a network
in the consumer's home.
The HAVi specification document can be downloaded from the
Sony external web site: http://www.sony.co.jp/HAVi/
|
|
HAVi-enabled
|
Any consumer Electronic (CE) device that is designed and
built to conform to the HAVi specifications for interactivity.
|
|
HDL
|
Acronym for Hardware Description Language. Language used
when designing logic. The most common HDLs in use today are
Verilog and VHDL.
|
|
HDL Bencher
|
Software tool used to graphically create HDL testbenches
for simulation.
|
|
HDLC
|
High-level Data Link Control. It is a bit-oriented synchronous
data link layer protocol developed by the ISO. It specifies
a data encapsulation method on synchronous serial links using
frame characters and checksums.
|
|
HDLC Controllers
|
These are devices which perform the HDLC protocol. Some of
the key operations include handling bit oriented protocol
structure and formatting data as per packet switching protocol
defined in the X.25 recommendations of the CCITT. It includes
transmitting and receiving the packeted data serially, while
providing the data transparency through zero insertion and
deletion. These controllers generate and detect flags that
indicate the HDLC status. They provide 16-/32-bit CRC on data
packets using the CCITT defined polynomial, and recognize
the single byte address in the received frame.
|
|
HDSL
|
High Speed Digital Subscriber Loop. A data protocol which
allows full duplex transmission of 772 kbps data over twisted
pair up to 20,000 feet.
|
|
HDSL
|
High data rate symmetric DSL - T1 or E1 speed achieve via
multiple modems and short distances.
|
|
HDTV
|
High Definition Television. Any one of a variety of video
formats offering greater visual accuracy (or resolution) than
current NTSC, PAL, or SECAM broadcast standards.HDTV has a
bandwidth of 300 MHz. HDTV is subjectively comparable to 35
mm film.
|
|
Header
|
The five bytes in an ATM cell that supply addressing and
control information, including generic flow control, virtual
path identifier, virtual circuit identifier, payload type,
and cell loss priority.
|
|
High-Pass Filter
|
A filter that passes high frequency signals
|
|
HiperLAN
|
High Performance European Radio LAN
|
|
HiperLAN2
|
Wireless LAN standard for the 5GHz spectrum, based on OFDM,
proposed by HiperLAN2 Global Forum.
|
|
Hold Time
|
Timing parameter that specifies the time the inputs need
to be held after a clock edge.
|
|
Home Network
|
A local area network (LAN) that connects the PCs in a home
and lets users access the Internet simultaneously, share drives,
share files and printers, and play head-to-head multi-player
games.
|
|
Home Networking
|
The vision of home networking includes the complete connection
of devices within the house to the Internet. It includes the
broadband access, residential gateway, interconnectivity technologies
and the different information appliances and includes the
distribution of audio, video and data between information
appliances.
|
|
Homebanking
|
Homebanking enables consumers to manage all banking directly
from their home, using their PC or their TV set together with
a Set-top Box.
|
|
HomePNA
|
Home Phoneline Networking Alliance. An association of 115+
industry-leading companies represented by PC, networking,
semiconductor sectors that was founded by 3Com, AMD, AT&T,
Compaq, Epigram (now Broadcom), HP, IBM, Intel, Lucent Technologies,
Conexant & Tut Systems. Xilinx is a member and an active
participant. This alliance ensures adoption of a single, unified
phoneline networking standard and rapidly bring to market
a range of interoperable home networking solutions.
|
|
HomeRF
|
A working group with the goal of enabling the existence of
a broad range of interoperable consumer devices by establishing
an open industry specification for unlicensed, RF digital
communications for PCs and consumer devices in and around
the home.
|
|
Homeshopping
|
Home or Teleshopping enables consumers to choose and order
goods directly from their home, using their PC or their TV
set together with a Set-top Box.
|
|
Host
|
A computer to which an expansion device attaches. When a
LAN card is installed in a PC, that PC is the host to that
adapter. It is also a time sharing computer accessed via terminals
or terminal emulation.
|
|
Hot Pluggable/ Insertion
|
Users can add or remove 1394 devices with the bus active
and there is no need to reset the bus.
|
|
Hot-Swapping
|
Attaching or removing peripherals with a simple 'Plug &
Play.' Hot swapping allows not to shut down and restart the
PC. The PC automatically detects the peripheral and configures
the necessary software. It is a useful feature for users of
multi-player games & notebook PC users who want to share
peripherals.
|
|
HP PCL
|
Hewlett-Packard Printer Control Language. The most popular
and widely emulated Escape Code printer language. PCL is available
in several variants including PCL 3 , 4, 5 and 6, each of
which provides more facilities than the previous variant.
|
|
HPGL
|
Hewlett-Packard Graphics Language, a vector graphics language
used by Hewlett-Packard plotters and commonly output by CAD
software. Some laser printers emulate HPGL to allow their
use with CAD packages.
|
|
HSSI
|
High Speed Serial Interface
|
|
HSTL
|
Acronym for High-speed Transceiver Logic. It is a high-speed
memory standard commonly used for QDR memory.
|
|
Hub
|
Hub connects high-performance stations/devices to Ethernet
local area networks and provides high-performance inter-LAN
connectivity using switching technology. Hub is a repeater
with fault detection functionality.
|
|
Hz
|
Hertz, Cycles per second. Used as the international unit
of frequency. It was named after Heinrich R. Hertz, a German
physicist.
|
|
I/O
|
Short for Input/Output, and pronounced eye-oh. I/O refers
to any operation, program, or device whose purpose is to enter
data into a computer or to extract data from a computer.
|
|
IAV (HAVi)
|
IAV is an acronym for Intermediate AV (device). This would
be a low-cost device with more limited functionality than
an FAV. An IAV would have vendor-specific functionality built
into it, but would not have the capability of allowing additional,
or upgraded JAVA applications to be installed on it by the
user. However, the ability to upgrade such a device would
still be possible, if the vendor provided a means to install
such applications or DCMs. These applications or DCMs would
most likely be platform specific, so they would have to come
from that specific vendor.
|
|
IC
|
Integrated Circuit
|
|
IDCT
|
Inverse Discrete Cosine Transform; used to recover data
sequence from the DCT transformed sequence.
|
|
IDL
|
Inter-chip Digital Link, a five-wire TDM interface defined
by Motorola.
|
|
IDSL
|
ISDN Digital Subscriber Loop (128kbps).
|
|
IEC
|
Abbreviation for International Electrotechnical Commission.
|
|
IEEE
|
Acronym for Institute of Electrical and Electronics Engineers.
A professional organization that sets standards.
|
|
IEEE 1394
|
Formal name for FireWire.
|
|
IEEE 1394 link layer
|
Link Layer provides data packet delivery service for the
two types of packet delivery: asynchronous and Isochronous.
As mentioned before, asynchronous isthe conventional transmit-acknowledgment
protocol and Isochronous is a real-time guaranteed-bandwidth
protocol for just-in-time delivery of information.
|
|
IEEE 1394 Transaction layer
|
The Transaction Layer supports the asynchronous protocol
write, read, and lock commands. A write sends data from the
originator to the receiver and a read returns the data to
the originator. Lock combines the function of the write and
read commands by producing a round trip routing of data between
sender and receiver including processing by the receiver.
|
|
IEEE 1394, 1394, FireWire, iLink
|
IEEE-1394 (also refers to as i.LINK or FireWire) is a specification
for data transfer between devices. It is the underlying network
technology for the HAVi protocols as well as for the transport
of the real-time AV streams. serial protocol that runs at
speeds ranging from 100 to 400 megabits per second, depending
upon the implementation. Devices that are prime candidates
for IEEE 1394 include digital camcorders and VCRs, digital
audio amplifiers, and video teleconferencing.
|
|
IEEE 1394b
|
IEEE 1394 (FireWire or iLink) is a hardware and software
standard for transporting data at 100, 200, 400, or 800 megabits
per second (Mbps). IEEE 1394b will be capable of transporting
data at 3.2 Gbps in 100 meter range.
|
|
IEEE 802.1
|
High Level Interface (HILI)
|
|
IEEE 802.10
|
Standards for Interoperable LAN Security (SILS)
|
|
IEEE 802
|
The IEEE 802 standards are a set of standards developed by
the IEEE to define methods of access and control on local
area networks. IEEE 802.11. The IEEE 802 standards are a set
of standards developed by the IEEE to define methods of access
and control on local area networks.
|
|
IEEE 802.11
|
Wireless LAN (WLAN). The 802.11 committee standard for 1
- 40 Mbps wireless LANs. The standard has a single MAC layer
for the following physical-layer technologies: Frequency Hopping
Spread Spectrum, Direct Sequence Spread Spectrum, Orthogonal
Frequency Division Multiplexing (OFDM) and Infrared.
|
|
IEEE 802.11 a
|
Wireless LAN standard for the 5GHz spectrum, based on OFDM,
proposed by IEEE
|
|
IEEE 802.11 b
|
Wireless LAN standard for the 2.4GHz spectrum, based on Ethernet,
proposed by IEEE.
|
|
IEEE 802.12
|
Demand Priority
|
|
IEEE 802.14
|
Cable-TV Based Broadband Communication Network
|
|
IEEE 802.15
|
Wireless Personal Area Network (WPAN)
|
|
IEEE 802.16
|
Broadband Wireless Access
|
|
IEEE 802.2
|
Logical Link Control (LLC)
|
|
IEEE 802.3
|
CSMA / CD
|
|
IEEE 802.4
|
Token Bus
|
|
IEEE 802.6
|
Metropolitan Area Network (MAN)
|
|
IEEE 802.7
|
Broadband TAG
|
|
IEEE 802.8
|
Fiber Optic TAG
|
|
IEEE 802.9
|
Integrated Services LAN (ISLAN)
|
|
Incremental Synthesis
|
Software feature that allows designers to safely make small
changes without impacting the rest of the design.
|
|
Information Appliances, Internet Appliances
|
An emerging category of digital consumer electronics that
provide the consumer with a low-cost, easy-to-use, instant-on
device, lightweight, reliable, special-purpose access to the
features and benefits of the Internet. Examples: PCs, PDAs,
servers, webphones, set-top boxes, peripherals, printers,
scanners, digital cameras, etc.
|
|
Ink Jet Printer
|
A printer technology where ink is splashed onto the printer
paper to form an image or character.
|
|
Inquiry (Bluetooth)
|
Inquiry is how a Bluetooth device learns about other devices
that are within its range. During the Inquiry process device
A continuously broadcasts the Page command using the reserved
Inquiry ID which identifies it as as a Page Inquiry. These
broadcasts are spread across a standard pattern of 32 Standby
radio frequencies which all devices in Standby mode monitor
on an occasional basis. Over a duration of some seconds it
is certain that every Standby device within range will have
received the Inquiry Page even though they are not synchronized
in any way. By convention these nodes will respond with a
standard FHS packet that provides their unique BT ID and their
clock offset. With these parameters the Inquiring node can
effect low latency synchronized connections.
|
|
Instruction Set
|
A basic command. The term instruction is often used to describe
the most rudimentary programming commands. For example, a
computer's instruction set is the list of all the basic commands
in the computer's machine language.
|
|
Integrated Services Digital Network (ISDN)
|
Series of CCITT recommendations related to the transmission
of voices and data down the same line.
|
|
Intellectual Property (IP)
|
Pre-defined logic function that can be used by designers
to speed up the design cycle.
|
|
Interface
|
An interface is a connection between electronic devices.
Examples: SCART, RS250, SCSI
|
|
Interframe coding
|
In video signal transmission, a way to compress the video
signal that concentrates on coding high-detail areas of a
picture at the expense of the less detailed areas.
|
|
Interlaced
|
The pattern described by two separate field scans when they
join to form a complete video frame.The two field scans interleave
together to form a single, complete frame.
|
|
internal 3-state bussing
|
A feature which allows multiple signals to be connected to
a single wire. Only 1 signal may be active at a time.
|
|
Internet
|
The largest network in the world. Being the successor to
ARPANET, the Internet includes other large internetworks.
The Internet uses the TCP/IP protocol suite and connects universities,
government agencies, and individuals around the world.
|
|
Internet Audio Player
|
A portable music player that plays back compressed music
stored in flash memory. Music is downloaded to the audio player
from the Internet using a PC with a cable connected to printer
port, USB or Bluetooth (that allows the system to exchange
music files untethered with the PC). Music sources include
CDs and downloading from Internet.
|
|
Internet Screenphones
|
High end desktop telephones with LCD screens that offer Internet
access for email message checking and informational services
and/or Web browsing. The phones include: base module, voice
communications module (corded or cordless handset and/or speakerphone),
keypad and screen display.
|
|
Internet Smart Handheld Devices
|
Vertical application devices that provide direct Internet
access capabilities using an add-on or integrated modem. These
include PDAs, personal companions, PC companions.
|
|
Intraframe
|
A lossy way to compress a video signal for transmission in
which half the picture information is eliminated by discarding
every other frame as it comes from the camera. During playback,
each frame remains on the screen twice the normal duration
to simulate the standard 30-frames-per-second video rate.
|
|
IO standards
|
Standardized interfaces making the design of new applications
much simpler.
|
|
IOB
|
Xilinx acronym for I/O block. Architectural block that contains
an I/O with additional features such as registers, latches,
clock enable and tristate control functions.
|
|
IOM-2
|
ISDN Oriented Modular Interface, a TDM interface defined
by Infineon.
|
|
IP
|
Internet Protocol. The protocol in TCP/IP that governs the
breakup of data messages into packets, the routing of the
packets from sender to destination network and station, and
the reassembly of the packets into the original data messages
at the destination. A Layer 3 (network layer in the ISO/OSI
model) protocol that contains addressing information and some
control information that allows packets to be routed. Documented
in RFC 791. The Internet standard protocol that defines the
Internet datagram as the unit of information passed across
the Internet. It provides the basis of the Internet connectionless
best effort packet delivery service. The Internet protocol
suite is often referred to as TCP/IP because IP is one of
the two fundamental protocols.
|
|
IP (Cores)
|
see intellectual property
|
|
IP address
|
A 32-bit binary number that uniquely identifies a host (computer)
connected to the Internet or to other Internet hosts, for
the purposes of communication through the transfer of packets.
Internet Protocol Address. This is a 32-bit address assigned
to host on a TCP/IP Internet. The IP address has a host component
and a network component.
|
|
IP capture
|
Xilinx tools that allow designers to convert customer in-house
created designs into IP cores that can be used in future designs.
Part of the Design Reuse flow.
|
|
IP center
|
Xilinx web site that centralizes information, data sheets,
and updates to Xilinx IPs that are created by Xilinx or AllianceCORE
partners.
|
|
IP multicast
|
The extension of LAN multicasting technology to a TCP/IP
network. Hosts send and receive multicast datagrams, the destination
fields of which specify IP host group addresses rather than
individual IP addresses. A host indicates that it is a member
of a group by means of the Internet Group Management Protocol.
|
|
IP portal
|
Web site that contains centralized information regarding
IP, intellectual property.
|
|
IP telephony
|
The ability to transmit voice using IP (packet-switched)
network.
|
|
IPoA
|
IP over ATM.
|
|
IPv6
|
Internet Protocol Version 6 (IPng, IPv6). IPv6 is a new version
of the Internet Protocol which is designed to be an evolutionary
step from its predecessor, version 4. There are many RFCs
defining various portions of the protocol, its auxiliary protocols,
and the transition plan from IPv4. The core RFCs are 1883
through 1886.
|
|
IR, Infrared
|
Infrared. Having a frequency in the electromagnetic spectrum
in the range just below that of red light. Objects radiate
infrared in proportion to their temperature. Infrared radiation
is divided into categories based on wavelength.
|
|
IRD
|
Abbreviation for Integrated Receiver Decoder. A Set-top Box
receiver with a built in descrambler for decoding Pay TV services.
|
|
IrDA
|
Infrared Data Association. The industry organization of computer,
component, and telecommunications vendors who have established
the standards for infrared communication between computers
and peripheral devices such as printers.
|
|
IRL
|
Acronym for internet reconfigurable logic. Ability for Xilinx
devices to be reconfigured through web based applications
making field updates easier.
|
|
ISA
|
Industry Standard Architecture. An 8-bit (and later, a 16-bit)
expansion bus that provides a buffered interface from devices
on expansion cards to the PC internal bus.
|
|
ISDN
|
Integrated Services Digital Network (ISDN) gives a user up
to 56 Kbps of data bandwidth on a phone line that is also
used for voice, or up to 144 Kbps if the line is only used
for data. ISDN is faster than a 56K dial-up modem but has
lost its appeal with the emergence of DSL lines. The growth
of ISDN has been flattening within the past few years but
it still may be a good solution where cable modem or DSL service
is not available. Analysts indicate there are approximately
2 million ISDN lines deployed in the U.S..
|
|
ISM band
|
Industrial, Scientific, Medical Band. This spectrum is freely
available worldwide with only a few basic equipment characteristics
regulated (i.e. must be spread spectrum and low power). The
major disadvantage of this band, especially for wireless communications,
is the great number of incompatible device types that share
it. These include cordless phones, microwave ovens, garage
door openers, low cost wireless video surveillance systems,
and numerous wireless LAN technologies. This means that the
ISM band is likely to be fairly noisy and will thus impact
data communications performance.
|
|
ISO
|
International Organization for Standardization
|
|
ISO/IEC JTC1 SC25 WG1
|
Informally called HomeGate and is operated by International
Standards Organization. It focuses on creating a set of communications
protocols for residential gateways.
|
|
Isochronous
|
Refers to a communication protocol based on time slices rather
than handshaking. For example, a process might have 20 percent
of total bus bandwidth. During its time slice, the process
can stream data.
|
|
Isochronous data transfer
|
IEEE 1394 supports two types of data transfer. Asynchronous
and Isochronous. Isochronous data transfer puts the emphasis
on the guaranteed timing of the data, and less emphasis on
delivery. Isochronous transfers are always broadcast in a
one-to-one or one-to-many fashion. No error correction nor
retransmission is available for Isochronous transfers. Up
to 80% of the available bus bandwidth can be used for Isochronous
transfers. The delegation of bandwidth is tracked by a node
on the bus Isochronous channel IDs are transmitted followed
by the packet data. The receiver monitors the incoming data's
channel ID and accepts only data with the specified ID.
|
|
ISP
|
Internet Service Provider. A commercial organization that
provides Internet access to individuals and organizations.
|
|
ISP
|
Internet Service Providers
|
|
ISP
|
Acronym for In-System Programmable. Ability to program a
device on the system board.
|
|
ITV
|
Interactive Television, based on a Back Channel interactive
TV, enables the consumer, e.g. to select his individual TV
program at any time or to take part in game shows, although
being at home.The acceptance of Interactive TV is presently
tested in various pilot runs all over the world.
|
|
Jamming
|
The typically intentional or malicious interference with
another radio signal.
|
|
Jbits
|
A Java based file format for configuring Xilinx FPGAs used
in IRL.
|
|
Jini
|
Jini network technology provides simple mechanisms which
enable devices to plug together to form an impromptu community
-- a community put together without any planning, installation,
or human intervention. Each device provides services that
other devices in the community may use. These devices provide
their own interfaces, which ensures reliability and compatibility.
Jini technology uses a lookup service with which devices
and services register. When a device plugs in, it goes through
an add-in protocol, called discovery and join-in. The device
first locates the lookup service (discovery) and then uploads
an object that implements all of its services' interfaces
(join).
To use a service, a person or a program locates it using
the lookup service. The service's object is copied from the
lookup service to the requesting device where it will be used.
The lookup service acts as an intermediary to connect a client
looking for a service with that service. Once the connection
is made, the lookup service is not i
|
|
Jitter
|
A type of analog communication line distortion caused by
abrupt, spurious signal variation from a reference timing
position, and capable of causing data transmission errors,
particularly at high speeds. The variation can be in amplitude,
time, frequency, or phase.
|
|
JPEG
|
Short for the 'Joint Photographic Experts Group'. This was
(and is) a group of experts nominated by national standards
bodies and major companies to work to produce standards for
continuous tone image coding. The 'joint' refers to its status
as a committee working on both ISO and ITU-T standards. The
'official' title of the committee is ISO/IEC JTC1 SC29 Working
Group 1, and is responsible for both JPEG and JBIG standards.
|
|
JPEG (Joint Photographic Experts Group)
|
The international consortium of hardware, software, and publishing
interests who, under the auspices of the ISO, has defined
a universal standard for digital compression and decompression
of still images for use in computer systems (commonly called
"JPEG" or "JPEG-Standard") JPEG compresses at about a 20:1
ratio before visible image degradation occurs.
|
|
JTAG
|
Acronym for Joint Test Action Group. Often refered to as
IEEE standard 1149.1. IEEE committee focused on chip interface
for testing and programming. Xilinx is a member of this committee.
|
|
Key Management
|
The overall process of generating and distributing cryptographic
keys to authorized recipients in a secure manner. In public
key cryptography key management includes the certification
of the relationship of specific public keys with specific
individuals or organizations by a trusted certificate authority.
|
|
Key Recovery
|
The ability of an individual, organization, or their authorized
agents to obtain an extra copy of a key (or other information
necessary for decryption) that enables them to decrypt the
ciphertext. In other words, key recovery is about ensuring
that there is a spare key available.
|
|
L2CAP (Bluetooth)
|
Logical Link Control and Adaptation Protocol. The L2CAP is
the layer that is responsible for managing the virtual connections
between Bluetooth devices and the first level of Asynchronous
ConnectionLess (ACL) data flow. Logical Link Control creates
and manages a virtual connection for each I/O task the host
gives it. This allows Bluetooth to support multiple concurrent
I/O transactions such as an internet connection and file transfer
proceeding simultaneously.
|
|
LAN
|
Local area network. A network interconnecting devices in
the same office, floor, or building, or areas inside buildings
with areas just outside. A group of PCs and other devices
dispersed over a relatively limited area and connected by
a communications link that enables any device to interact
with any other device on the network.
|
|
LAPD (Link Access Procedure for D channel)
|
The data link layer protocol that was defined for communication
over the D channel. It is based on HDLC and defined in the
I.441/Q.921 specifications.
|
|
LARQ
|
Limited automatic repeat request
|
|
Laser Printer
|
A type of printer that utilizes a laser beam to produce an
image on a drum. The light of the laser alters the electrical
charge on the drum wherever it hits. The drum is then rolled
through a reservoir of toner, which is picked up by the charged
portions of the drum. Finally, the toner is transferred to
the paper through a combination of heat and pressure. This
is also the way copy machines work.
|
|
Latch
|
A basic logic function that stores the input value of a signal.
Unlike a flip flop, the output directly reflects the input
value when enabled.
|
|
Latency
|
In general, the period of time that one component in a system
is spinning its wheels waiting for another component. Latency,
therefore, is wasted time. For example, in accessing data
on a disk, latency is defined as the time it takes to position
the proper sector under the read/write head. In networking,
the amount of time it takes a packet to travel from source
to destination. Together, latency and bandwidth define the
speed and capacity of a network.
|
|
LAV (HAVi)
|
LAV is an acronym for Legacy AV devices.
LAV devices are existing devices that were designed prior
to the development of HAVi and therefore are not 'HAVi aware'.
Typical examples are current DV camcorders.
|
|
LCD
|
Acronym for Liquid Crystal Display. A low power display,
such as a watch or calculator.
|
|
LCD Printer
|
Similar to a laser printer. Instead of using a laser to create
an image on the drum, however, it shines a light through a
liquid crystal panel. Individual pixels in the panel either
let the light pass or block the light, thereby creating a
dot image on the drum.
|
|
Leased Line
|
Any circuit or combination of circuits designated to be
at the exclusive disposal of a given subscriber. Synonym:
Private line; Full Period Line.
|
|
LEC
|
Local Exchange Carrier - also commonly known as your local
phone company. The supplier of phone and communications within
a specific city or geographic region.
|
|
LED Printer
|
An electrophotographic printer that uses a matrix of LEDs
as its light source. The LED mechanism is much simpler than
its laser printer counterpart. A stationary array of LEDs
is used instead of numerous moving parts, and the LEDs are
selectively beamed onto the drum.
|
|
Link
|
Covers framing, synchronization, error control, and flow
control.
|
|
Link Manager (Bluetooth)
|
The link manager layer in Bluetooth is the module that physically
creates (connects), configures (QoS agreement, security provisions,
etc.), and terminates all device to device links.
In ACL data flow the link manager also transfers data from
the L2CAP to the baseband and back. On the way down it passes
the data to the baseband with the appropriate control information
for the target link (i.e. target device ID, encryption parameters,
etc.) and on the way up it associates the incoming data to
the source link for the L2CAP.
|
|
Liquid Audio
|
Based in Redwood City, Liquid Audio is the pioneer and current
market leader in downloadable media commerce technology on
the Internet. The company derives its revenue from the delivery
of software products including authoring tools, and servers
for media commerce; as well as media commerce services. While
the Liquid Audio media architecture can support multiple audio
coding standards, the default codec is based on AAC and includes
copy protection features.
|
|
LLC
|
Logical Link Control (LLC. IEEE-defined sub layer of the
OSI link layer that handles error control, flow control, and
framing. The most revalent LLC protocol is IEEE 802.2, which
includes both connectionless and connection-oriented variants.
|
|
LMDS
|
Cellular cable.
|
|
LNB
|
Low Noise Block Converter. Usually mounted at the focal point
of the dish and used to amplify and convert satellite signals
into frequencies sent to the receiver.
|
|
Local bus
|
Usually refers to a system bus directly connected to the
microprocessor on a system board. It also refers to system
board buses located closer to the microprocessor than are
ordinary expansion buses (that is, with less buffering), which
are therefore capable of greater throughput.
|
|
Logic Cell
|
Metric used to compare various FPGA device densities.
|
|
LogicCORE
|
Xilinx created logic functions. Can be accessed with CORE
Generator.
|
|
Loop
|
Twisted-pair copper telephone line.
|
|
Lossless compression
|
A compression technique that preserves all the original information
in an image or other data structures.
|
|
Lossy compression
|
A compression technique that improves data reduction by discardingunnecessary
image information.
|
|
Low-Pass Filter
|
A filter that passes low frequency signals.
|
|
LUT
|
Acronym for Look-Up Table. A LUT can implement any logic
function of its inputs.
|
|
LVCMOS
|
Acronym for Low Voltage CMOS. Common I/O standard for chip
to chip interfaces.
|
|
LVTTL
|
Acronym for Low Voltage TTL. Common I/O standard for chip
to chip interfaces.
|
|
MAC
|
Media Access Control. Sub-layer of Data Link Control; defined
by the IEEE, as the lower portion of the OSI reference model
data link layer. It is responsible for mapping hardware addresses
to network traffic. The MAC sub layer is concerned with media
access issues, such as whether token passing or contention
will be used.
|
|
Machine Language
|
The lowest-level programming language (except for computers
that utilize programmable microcode) Machine languages are
the only languages understood by computers. While easily understood
by computers, machine languages are almost impossible for
humans to use because they consist entirely of numbers. Programmers,
therefore, use either a high-level programming language or
an assembly language. An assembly language contains the same
instructions as a machine language, but the instructions and
variables have names instead of being just numbers.
|
|
Macro
|
Pre-defined function that designers can drop into their design,
e.g. a counter or adder
|
|
MAN
|
Metropolitan Area Network. Public network service to provide
LAN facilities over a wide area. Similar to a LAN but typically
deployed over a larger area like a city.
|
|
Manual Power Down Mode
|
It is the amount of electrical energy consumed by the device
for its operation.
|
|
MAOSCO
|
Multi-Application Operating System Company
|
|
Map
|
Software process of converting a designer's original design
file into FPGA specific features.
|
|
Master
|
The Master or Initiator owns the bus and initiates the data
transfer. Each Initiator must also be a target.
|
|
Master State (Bluetooth)
|
Maintains control of a Piconet
|
|
MCNS
|
Multimedia Cable Network System
|
|
MCPC
|
Multiple Channel Per Carrier.
|
|
MCU
|
Microcontroller Unit
|
|
MD, MiniDisc
|
MD or MiniDisc is a small-format optical storage medium with
read/write capabilities. This was pioneered by Sony in 1993.
|
|
Media
|
Anything which a laser printer can print on, e.g. paper,
card, transparencies and labels.
|
|
Megabyte
|
Amount of memory equal to 1,048,576 bytes of information
(Abbreviated MB).
|
|
MEL
|
MULTOS Executable Language
|
|
Memory
|
Internal storage areas in the computer. The term memory identifies
data storage that comes in the form of chips, and the word
storage is used for memory that exists on tapes or disks.
|
|
Memory Controller
|
An ASIC or FPGA which interfaces with a memory and enables
data transfer.
|
|
Memory Corner
|
A location on the Xilinx web site that talks specifically
about Xilinx memory solutions. It has links to application
notes and reference designs.
|
|
Messaging System (HAVi)
|
One of the Software Elements that comprise the basic mechanisms
in HAVi to achieve interoperability. Each element provides
a certain functionality. The Software Elements that are needed
for interoperability between HAVi devices are the Messaging
System, the Registry, the Event Manager, the Resource Manager,
the Stream Manager and the DCM.
|
|
MFP
|
Multifunction Peripheral.Today, this means the class of
devices that scan, copy, print and FAX.
|
|
MHz
|
Abbreviation for MegaHertz. One MHz represents one million
cycles per second. The speed of microprocessors, called the
clock speed, is measured in megahertz.
|
|
Microcontroller
|
A highly integrated chip that contains all the components
comprising a controller. Typically this includes a CPU, RAM,
some form of ROM, I/O ports, and timers. Unlike a general-purpose
computer, which also includes all of these components, a microcontroller
is designed for a very specific task -- to control a particular
system. As a result, the parts can be simplified and reduced,
which cuts down on production costs.
|
|
Microprocessor
|
A silicon chip that contains a CPU. In the world of personal
computers, the terms microprocessor and CPU are used interchangeably.
At the heart of all personal computers and most workstations
sits a microprocessor. Microprocessors also control the logic
of almost all digital devices, from clock radios to fuel-injection
systems for automobiles.
|
|
Microprocessor
|
A silicon device that contains a CPU. Microprocessors control
the logic of almost all digital devices, e.g. PCs, workstations,
clock radios, and fuel-injection systems for automobiles.
|
|
Microwave
|
Usually referring to all radio frequencies above 2 GHz.
|
|
MII
|
Media Independent Interface
|
|
MMDS
|
Microwave Multichannel Distribution System is a distribution
service for TV signals using microwave transmissions. Also
called multichannel video distribution system (MVDS). In the
US, it is called "wireless cable".
|
|
Modem
|
Modulator/Demodulator. A device for converting digital data
to audio tone and (vice versa) for transmission on an analog
channel.
|
|
Modular Design
|
Modular design allows mutilpe designers to simultaneously
develop individual blocks thereby shortening the design cycle.
|
|
Modulate
|
To vary the amplitude, frequency or phase of a radio frequency
wave in accordance with the information to be conveyed.
|
|
Modulation
|
Any of several techniques for combining user information
with a transmitter's carrier signal.
|
|
Modulation
|
QAM, QPSK, OFDM
|
|
MP3
|
MP3 (MPEG Layer III Audio Coding) The MPEG Layer 3 audio
compression scheme that was defined as part of the International
Standards Organization (ISO) Moving Picture Experts Group
(MPEG) audio/video coding standard. MPEG-I defined three encoding
schemes, referred to as Layer I, Layer II, and Layer III.
Each of these schemes uses increasing sophisticated encoding
techniques and gives correspondingly better audio quality
at a given bit rate. The three layers are hierarchical, in
that a Layer III decoder can decode Layer I, II, and III bitstreams;
a Layer II decoder Layer II, and I bitstreams; and a Layer
I decoder only Layer I bitstreams. Each of the layers support
decoding audio sampled at 48, 44.1, or 32 kHz. MPEG 2 uses
the same family of codecs but extends it by adding support
for 24, 22.05, or 16 kHz sampling rates as well as more audio
channels for surround sound and multilingual applications.
|
|
MPEG
|
Motion Picture Experts Group. Industry organization developing
standards and specifications for the encoding, digitization,
compression and transmission of video information over various
media and network technologies. MPEG-1 is a standard for transmission
of QCIF (1/4 screen) pictures at the primary data rate of
1.54 MHz, resulting in VCR quality video. MPEG-2 is much more
extensive, including a definition of a high-quality video
picture.
|
|
MPEG Audio Layers
|
MPEG-1 and MPEG-2 both have a three-layer structure, each
of which represents a family of coding algorithms. These layers
are noted in the standards using Roman figures (Layer I, Layer
II, and Layer III). Note that for Internet audio applications
MPEG-1 Layer III audio has become known as MP3.
|
|
MPEG Stages
|
The generations of standards defined by the MPEG working
group are referred to as stages. These stages are normally
noted in Arabic figures (MPEG-1, MPEG-2, and MPEG-4).
|
|
MPEG-2
|
MPEG-2 is a video compression standard being developed for
bitrates from 3 - 15 Mbit/s.
|
|
MPEG-2 AAC (Advanced Audio Coding)
|
AAC (Advanced Audio Coding) is one of the audio compression
formats defined by the MPEG-2 standard. AAC used to be called
NBC (Non-Backward-Compatible), because it is not compatible
with the MPEG-1 audio formats. MPEG-2 also defined another
audio format called MPEG-2 Multichannel or MPEG-2 BC (Backward
Compatible), which is compatible with MPEG-1. AAC is more
efficient than MP3 (MPEG-1 Layer III) and is the state of
the art in audio compression technology. Formal listening
tests have demonstrate it is able to provide slightly better
audio quality at 96 kb/s than layer-3 at 128 kb/s or layer-2
at 192 kb/s.
|
|
MPEG-4
|
Developed by same group supporting MPEG-1 and MPEG-2, this
new A/V codec with better compression capabilities than previous
standards & additional interactive support.
|
|
MultiLINX Cable
|
It is used to program (configure) and debug Xilinx FPGAs
and CPLDs.
|
|
Multipath Fading
|
A type of fading caused by signals taking different paths
from the transmitter to the receiver and, consequently, interfering
with each other.
|
|
Multipath Interference
|
Signal reflections and delayed signal images which are typically
associated with indoor wireless LAN applications, and interfere
with the desired signal.
|
|
Multiple Access
|
A method for accommodating more users in the same frequency
band.
|
|
Multiplex
|
A stream of all the digital data carrying one or more services
within a single physical channel.
|
|
Multipoint
|
A communications circuit interconnecting several nodes (usually
more than two).
|
|
Nanosecond
|
A billionth of a second. Many computer operations, such as
the speed of memory chips, are measured in nanoseconds. Nanosecond
is often abbreviated as ns.
|
|
Narrowband
|
A signal where the transmission bandwidth is on the order
of its information bandwidth.
|
|
NCO
|
Acronym for Numerically Controlled Oscillator. Type of IP
used in creating sine/cosine applications.
|
|
Netlist
|
A file that describes the logic and the connections of a
circuit or a system.
|
|
NetTV
|
TV-centric information appliances that provide Internet access
and use the TV as their primary display. These are standalone
products that are set on top of the TV ("set-top").
These include TVs with Internet connectivity built in at the
time of manufacture. Examples: set-top boxes, integrated TVs,
enhanced traditional cable boxes, direct satellite devices.
|
|
Network
|
A collection of MPEG-2 Transport Stream multiplexes transmitted
on a single delivery system, e.g. all digital channels on
a specific cable system.
|
|
Network Address
|
A unique number associated with a host that identifies it
to other hosts during network transactions.
|
|
Network layer
|
The Network Layer controls the operation of the network or
sub-network (or sub-net). It decides which physical pathway
the data should take based on network conditions, priorities
of service, and other factors.The Network Layer relieves the
upper layers of the need to know anything about the data transmission
and switching technologies used to connect systems. It is
responsible for establishing, maintaining, and terminating
connections across the intervening communications facility.
|
|
Network Printer
|
A printer which is designed to connect to a network and
be used by groups of users, a sub-class of workgroup printers.
|
|
NIC
|
Network Interface Card. The circuit board or other hardware
that provides the interface between a communicating DTE and
the network. It allows communications with other stations
and usually refers to a network adapter card which installs
in a computer.
|
|
NIST
|
National Institute of Standards and Technology
|
|
NoBL SRAM
|
No Bus Latency SRAM
|
|
Node
|
Any network station
|
|
Noise
|
An ever present unwanted background signal that needs to
be compensated for or removed.
|
|
Non encoded PST
|
Data modulated by PSK (Phase Shift Keying) that is not modified
by the Reed-Solomon encoder before transmission.
|
|
Non-volatile
|
Type of memory or configuration that retains programmed information
even when power is removed from the device. Examples of Non-volatile
memory are EPROM or Flash-based CPLDs.
|
|
NT (ISDN)
|
Network Terminator
|
|
NT1 (Network Termination Equipment for layer 1)
|
Equipment that terminates the ISDN network connection at
OSI layer 1 (the physical layer). Specifically it terminates
the U interface and converts it into an S/T interface.
|
|
NT2 (Network Termination Equipment for layer 2)
|
Equipment that terminates the ISDN network interface at OSI
layer 2, (the data link layer). An example would be a PBX
that terminates a PRI connection and provides several BRI
interfaces. An NT2 interfaces to TAs or TE1s via an S interface
and to an NT1 via a T interface.
|
|
NTSC
|
The color TV system established by the US National Television
Standards Committee which is used in North America, Japan
and their dependents. NTSC produces interlaced 525 line 30
frames/pictures.
|
|
NTSC format
|
A color television format used in the United States. See
also PAL, SECAM.
|
|
NVOD
|
Near Video On Demand. Term properly describing movie service,
but now generally referring to all types of near-on-demand
services where viewers are able to order and see a given program
on an individual basis at a given time interval.
|
|
OC-12
|
Optical Carrier 12 (OC-12). The optical carrier level equivalent
to SONET STS-12 at 622.08 Mbps.
|
|
OC-3
|
SONET Optical Carrier, running at 155 Mbps. It is equivalent
to SDH STM-1 in Europe.
|
|
OEM
|
Original Equipment Manufacturer. A manufacturer of products
for integration in other products or systems.
|
|
OFDM
|
Orthogonal Frequency Division Multiplexing
|
|
OFDM
|
Orthogonal Frequency Division Multiplecxing. Single high-frequency
carrier is replaced by multiple subcarriers, each operating
at a significantly lower frequency. It is a special method
of multi-carrier modulation. Like all wireless transmission
schemes, OFDM encodes data onto a radio frequency (RF) signal.
OFDM transmits multiple high data rate signals concurrently
on different frequencies. The channel spectrum is passed into
a number of independent non-selective frequency sub-channels
and these subchannels are used for one transmission link between
the access point and mobile terminals.
|
|
Office Printer
|
A printer which is designed for general purpose office use,
and may be used by an individual user, or shared by a small
group of users.
|
|
One Dimension
|
A one dimension is composed of a single array of element
N in size.
|
|
Online gaming
|
Interactive electronic game playing with offsite, independent
variables such as another human opponent or an offsite PC.
|
|
Online Services
|
Online Services are commercial networks providing information
in a certain structure to their customers. They also offer
communication tools like E-Mail, Chat-Lines a.s.o. The most
popular commercial Online Services are America Online, CompuServe
and Microsoft Network.
|
|
Optical Carrier (OC-n)
|
Fundamental unit in the SONET (Synchronous Optical Network)
hierarchy. OC indicates an optical signal; n represents increments
of 51.84 Mbps. Thus, OC-1, -3, and -12 equal optical signals
of 51, 155, and 622 Mbps.
|
|
optimize
|
The process of decreasing a designs area and/or increasing
its performance.
|
|
OSGi
|
The Open Services Gateway Initiative (OSGi) is an industry
group working to define and promote an open standard for connecting
the coming generation of smart consumer and small business
appliances with commercial Internet services. For more information
please visit: www.osgi.org.
|
|
OSI
|
OSI Reference Model. The seven-layer network architecture
model of data communication protocols developed by ISO and
CCITT to facilitate interconnection of disparate computer
networks. Each layer specifies particular network functions
such as addressing, flow control, error control, encapsulation,
and reliable message transfer.
|
|
Outline Font
|
A font in which each character is represented by sets of
equations or vectors which define the outline of the character.
An outline font cannot be printed "as is", but must first
be scaled to the appropriate size, and "filled" with dots
to make a bitmap. As outline fonts can be scaled they may
be used to create characters of any size, and may be rotated
to any angle.
|
|
P.P.M.
|
An abbreviation of pages per minute. See speed.
|
|
Package
|
The material that surrounds the die or chip. The package
protects the electronic circuitry.
|
|
Packet
|
A basic message unit for communication across a network.
A packet usually includes routing information, data, and (sometimes)
error detection information.
|
|
Packet Switched Network
|
Network that does not establish a dedicated physical path,
but transmits data in segments called packets. Packets are
sent over the best available network connection and then re-assembled
at the end-point.
|
|
Packet Switching
|
Packet switching technologies are based on end stations collecting
data to be transmitted into packets.Packets may be variable
in length or may be of a fixed size, as in ATM. Packets may
be transmitted at any time without the setup of a connection
with the destination.It is up to the network to determine
how to route the data to the destination. At the same time
the network does not guarantee delivery and it is up to the
end stations to provide mechanisms for reliable delivery.
Most data communications technologies are based on packet
switching. The use of packet switching is driven by the underlying
assumption that computer data traffic is inherently bursty
in nature, and not time-critical.
|
|
Packet-switched network
|
A communications network that uses shared facilities to route
data packets from and to different users. Unlike a circuit-switched
network, a packet-switched network does not set up dedicated
circuits for each session.
|
|
PAL format
|
Phase Alternation Line - the European color television format.
See NTSC, SECAM.
|
|
PALplus
|
PALplus is the name of a strategy group formed in 1989 to
develop an enhanced terrestrial transmission system compatible
with conventional PAL. The group, made up of German, Austrian,
Swiss and British broadcasters as well as Philips, Thomson,
Grundig, Nokia, Sony and Samsung, set itself the task of enhancing
the PAL signal by developing the 16:9 letterbox format, increasing
the useable luminance bandwidth, reducing cross-color artifacts,
working on echo cancellation and improving sound.
|
|
PAN
|
Personal Area Networks
|
|
Parallel Cable III
|
The Xilinx Parallel Cable III is a download cable connected
to the parallel port of the PC. It is used to program Xilinx
FPGAs and CPLDs using the JTAG interface.
|
|
Parallel Interface
|
A communication mechanism used to transfer data from a computer
to a printer, several bits at a time. Most parallel interfaces
are 8 bits wide, and thus transfer one byte in each transaction,
however a few are 16 bits wide, transferring two bytes simultaneously.
|
|
Parallel Multiplier
|
Type of IP that multiplies all input bits of the multiplier
simultaneously.
|
|
Parallel Port
|
An I/O channel for a parallel device, like a printer. Increasingly,
other devices such as removable storage drives, scanners etc.
share the printer parallel port using a 'pass through' mechanism.
|
|
Parameratizable
|
Refers to the ability to change the size of an IP core based
on the designer's requirements, e.g. width of bus. Parameters
are entered by using the Xilinx CORE Generator.
|
|
Parking (Bluetooth)
|
Parking is a mechanism that allows a Bluetooth Master to
connect to an additional 256 devices. 256 is a hard limit
as 8 bits are allocated in Bluetooth for the Parked Member
Address (PMA).
To Park a device the Bluetooth Master issues a Park command
to an Active Slave and assigns it a PMA. This Slave then enters
the Parked mode and surrenders its AMA. As a Parked Slave
the device will revert to a passive mode and only monitor
for commands on an occasional basis. The difference between
Standby and Parked however is that the Slave will remain synchronized
to the Master's hopping pattern and regularly update its clock
offset. Thus this device can be reconnected at any time with
a minimum latency.
|
|
Partial reconfiguration
|
The ability to reprogram a portion of the FPGA. This allows
a user to update part of a Xilinx FPGA while the remaining
part is being used. Other vendors do not have this feature.
|
|
Passive Slave State (Bluetooth)
|
Part of a Piconet but in a inactive and low power, but occasionally
monitoring and still synchronized state.
|
|
Pay TV
|
Encrypted TV programs, which can only be accessed by subscribers,
using entitled smart cards of the broadcasters. Generally
Pay TV is distinguished into two categories: 1. Pay per Channel
Customers subscribe on a monthly basis a package of TV channels.
2. Pay Per View Customers pay for viewing one single movie
or, e.g. sports event which is selected individually from
the TV channels. The smart card registers the access to the
program in order to charge the customer for the selected service.
|
|
PBSRAM
|
PBSRAM stands for Pipeline Burst SRAM. The PBSRAM devices
have input and output registers for data, which are not incorporated
into the flow-through device. This allows the pipelined device
to operate with a much faster cycle time than the flow-through
version.
|
|
PBX
|
Private Branch Exchange, a private telephone network.
|
|
PC
|
Personal Computer
|
|
PC100 DRAM
|
A Type of DRAM used to support 100MHz system bus speed.
|
|
PCF
|
Point Coordination Function
|
|
PCI
|
Peripheral Component Interconnect. A high-performance, 32-bit
or 64-bit bus designed to be used with devices that have high
bandwidth requirements, such as the display subsystem. It
is a standard interface defined by the computer industry for
local bus interconnection between microprocessors and other
peripherals in a system (memory controllers, extended bus
interfaces, and graphics controllers).
|
|
PCI SIG
|
The PCI Special Interest Group (SIG) is an unincorporated
association of members of the microcomputer industry set up
for the purpose of monitoring and enhancing the development
of the PCI architecture. The SIG is led by a nine member steering
committee and governed by SIG bylaws.
|
|
PCL
|
Printer Command Language, normally in reference to Hewlett-Packard
Printer Command Language (HP PCL), but most manufacturers
emulating HP PCL leave out the HP.
|
|
PCM
|
Pulse Code Modulation. Method of modulation in which analog
voice signals are sampled and converted to digital words that
are then transmitted serially. Most PCM systems use either
7- or 8-bit binary codes. There are, however, several standards
for PCM coding: most common are µ-Law in North America and
A-Law in Europe (both based on logarithmic conversion of the
signal). Requires sampling the analog signal 8 thousand times
per second and converting the sample to an 8-bit value. Hence,
PCM requires a 64 Kbps digital channel to carry one voice
connection.
|
|
PCMCIA
|
Personal Computer Memory Card International Association (PCMCIA)
PC card. A credit card-size device originally designed as
a platform for add-on memory for portable computers, but later
expanded to include a wide range of peripherals including
pagers and radio modems.
|
|
PCP
|
Parallel Control Port, used by Motorola for a standard microprocessor
bus port.
|
|
PCS
|
PCS (Personal Communication System) is a new lower power
high frequency competitive technology to cellular operating
at 1.5 to 1.8 Ghz range. It is usually associated with cordless
telephone-like devices and PDA devices. Service is typically
digital.
|
|
PDA
|
PDAs (Personal Digital Assistant) are primarily a productivity
and communications tool that is lightweight, compact, durable,
reliable, easy to use, and integrates into existing operations.
PDAs fall into four categories: Handheld PCs (HPCs), Palm-size
PCs (PPCs), Smart phones, Handheld instruments.
|
|
PDL
|
Page Description Language: a language for describing the
layout and contents of a printed page used with laser printers.
The best-known PDLs are Adobe PostScript and HP PCL (Printer
Control Language). Both PostScript and modern versions of
PCL are object-oriented, describing a page in terms of geometrical
objects such as lines, arcs, and circles.
|
|
PDP
|
Plasma display panels
|
|
peer-to-peer network
|
A network design in which each PC shares and uses devices
on an equal basis. All nodes on the network have equal access
to and control of the network medium.
|
|
Performance
|
Here, the device goes into low power mode consuming minimal
amount of current. Excellent for long periods of inactivity
or minimal activity.
|
|
Personal Printer
|
A small printer, typically producing 4 - 5 p.p.m, which is
physically compact to allow easy use on a desk, and sufficiently
inexpensive to justify if ownership by an individual for their
personal printing needs.
|
|
Phase jitter
|
Abrupt, spurious variations in an analog line, generally
caused by power and communication equipment along the line
that shifts the signal phase relationship back and forth.
|
|
Phase Linearity
|
The delay in the output sequence in relation to the input
sequence is characterized by a linear relationship.
|
|
Phase shift
|
Creating a signal that is delayed by some percentage of the
clock cycle.
|
|
PHY, Physical Layer
|
PHYsical layer. The bottom layer of the OSI and ATM protocol
stack, which defines the interface between the different physical
media. The PHY consists of two sublayers: the transmission
convergence (TC) sublayer and the physical medium-dependent
(PMD) sublayer. he nuts and bolts layer, where the cable,
connector and signaling specifications are defined . The Physical
layer transmits the unstructured raw bit stream over a physical
medium, and describes the electrical, mechanical, and functional
interface to the carrier. It is this layer that provides the
linking to the upper sessions via signaling. (example of this
kind of signal interface would be RS-232).
|
|
Piconets (Bluetooth)
|
Master device with 1 to 7 Active Slave devices
|
|
PID
|
Packet Identifier. PID is a code used for identifying the
components that form a particular service in the transmitted
datastream.
|
|
Piezo-Electric
|
The property of certain crystals that causes them to oscillate
when subjected to electrical pressure (voltage).
|
|
Pigment Inks
|
While conventional inks are essentially oil-based dyes, pigment
inks consist of tiny chunks of solid pigment suspended in
a liquid solution. According to their proponents, pigment
inks offer richer, deeper colors and have less tendency to
run, bleed or feather.
|
|
PIN
|
Personal Identification Number
|
|
Pixel
|
A "picture cell element", commonly used as a misnomer for
a dot in laser printing. It is a misnomer because a laser
printer dot is an indivisible unit, whereas a pixel may actually
comprise several dots arranged in a matrix to form a shade
of gray.
|
|
Place
|
The process of assigning logic from your design to physical
cell locations in the FPGA. The process done prior to routing.
|
|
Plaintext
|
The original message
|
|
PLCC
|
Plastic Leaded Chip Carrier package. Type of surface mount
device package.
|
|
PLL
|
Acronym for Phase Locked Loop. An analog circuit used to
perform clock management functions on and off-chip.
|
|
Plug and Play
|
A design philosophy and set of specifications that describe
hardware and software changes to the PC and its peripherals
that automatically identify and arbitrate resource requirements
among all devices and buses on the system. Plug and Play also
specifies a set of API elements that are used in addition
to (not in place of) existing driver architectures.
|
|
Plug-In
|
Plug-in is a control networking protocol developed by Intelogis
|
|
PMA (Bluetooth)
|
Parked Member Address
|
|
PMD
|
Physical Medium Dependent. A sublayer of the physical layer
that interfaces directly with the physical medium and performs
the most basic bit transmission functions of the network.
|
|
PN
|
Pseudo Noise. A digital signal with noise-like properties.
|
|
PNA
|
Phone Networking Alliance - Home networking standard for
1-10 Mbps over phone wire.
|
|
Point of Presence (POP)
|
A physical location within a Local Access and Transport Area
(LATA) at which an inter-exchange carrier establishes itself
for the purpose of obtaining LATA access.
|
|
Point-to-multipoint
|
A communications channel that runs from one point to several
other points.
|
|
Point-to-Point
|
A (temporary) separate connection between a service provider
and one receiver. (E.g. VOD service)
|
|
POS
|
Point of Sale (Terminal)
|
|
PostScript
|
A page description language developed by Adobe. Generally
used by laser printers, PostScript is becomingincreasingly
common in high-end ink jets too.
|
|
POTS
|
Plain Old Telephone Service. It refers to analog telephone
service, at nominal 0-3 kHz bandwidth.
|
|
POTS Splitter
|
A device that rejects the DSL signal and allows the POTS
frequencies to pass through.
|
|
Power
|
It is the time required by the device to go from the normal
operating mode to the Power Down Mode.
|
|
Power Down Mode
|
An operating condition where the device consumes minimal
amount of current. Excellent for portable applications.
|
|
Power Down Time
|
It is the time required by the device to go from the normal
operating mode to the Power Down Mode.
|
|
Power meter
|
A device used to measure radio energy.
|
|
Power Save Mode - "Sleep" mode
|
Provisions are made in the protocol for the portable stations
to go to low power "sleep" mode during a time interval defined
by the base station. The client is unable to communicate,
but the sleep mode consumer less power.
|
|
PPP
|
Point-to-Point Protocol. A data link protocol developed by
the Internet Engineering Task Force for dialup telephone connections,
such as between a computer and the Internet.
|
|
PPV
|
Pay Per View.Customers pay for viewing one single movie or,
e.g. sports event which is selected individually from the
TV channels. The smart card registers the access to the program
in order to charge the customer for the selected service.
|
|
Preamble
|
Symbols at the beginning of the frame that support robust
carrier sensing & collision detection, equalizer training,
timing recovery & gain adjustment.
|
|
Presentation
|
Normalizing data syntax between applications
|
|
Presentation layer
|
The Presentation Layer formats the data to be presented to
the Application Layer. It can be viewed as the translator
for the network. The Presentation Layer provides a common
representation for data that can be used between application
processes.
It includes: Encoding data, Compressing data to reduce the
number of bits transmitted, Encrypting data for privacy and
authentication.
|
|
PRI (Primary Rate Interface)
|
Primary Rate ISDN service is targeted at larger corporate
customers. PRI service consists of 23 B channels in North
America and is transported across a standard T1 physical layer
interface. In Europe the service provides 30 B channels plus
one 64 kbps D channel and uses an E1 physical layer. PRI requires
two sets of twisted pair telephone lines.
|
|
Print Cartridge
|
A print cartridge is a printer consumable which normally
contains all the major replaceable elements in a laser printer,
such as toner, and developer.
|
|
Print Engine
|
The mechanism which transcribes a bitmap created by the
printer controller into a printed image.
|
|
Printer Controller
|
The dedicated computer in a printer which receives data to
be printed from a computer, along with commands defining how
the data should be formatted, and uses these to create (rasterize)
a bitmap describing the image required on the paper which
is then passed to the print engine for transcription to the
paper.
|
|
Printer Dot
|
The individual pixel in a halftone image. The size of a
printer dot is variable, ranging from zero (all white) to
the size of the halftone screen (all black).
|
|
Printer Driver
|
A software utility incorporated into a software application
package on a computer which enables the application to determine
the commands required by the printer to format data for printing,
and which provides the application with information about
the facilities provided by the printer.
|
|
Private Key
|
The privately held decryption key. It is unknown to the public
and difficult to determine mathematically.
|
|
PRNG
|
Pseudo Random Number Generator
|
|
Production Printer
|
A large heavy-duty printer designed for almost continuous
printing in a production environment, either for large quantities
of small documents such as invoices and account statements,
or for small quantities of large documents such as reports,
short-run books, newsletters etc.
|
|
Program
|
A concatenation of one or more events under the control of
a broadcaster, e.g. news show, entertainment show.
|
|
Programming
|
Process of storing data into memory devices, e.g. EPROM,
EEPROM, or FLASH, often used for configuration of FPGA's.
Sometimes used synonymously as configuration.
|
|
PROM
|
Acronym for Programmable Read Only Memory. A device that
is typically used to hold data to configure (program) FPGAs.
|
|
Propogation
|
The travel of a signal through a medium such as air or free
space.
|
|
Protocol Data Unit (PDU)
|
A discrete piece of information such as a packet or frame.
It is in the appropriate format to be segmented and encapsulated
in the payload of an ATM cell.
|
|
Protocols, Communications Protocols
|
A set of rules or standards designed to enable computers
to connect with one another and to exchange information with
as little error as possible. These rules are set for communicating,
particularly for the format and transmission of data.
|
|
PSI
|
Abbreviation for Program Specific Information.
|
|
PSTN
|
Public Switched Telephone Network. It is a Wide Area Network
(WAN) that is available to all users in a region, whicih compares
to private networks that are owned or leased by individual
companies or subscribers. In some regions of the world, the
PSTN is operated by government entities, while in others they
are operated by public utility companies. The PSTN is evolving
now into the global Public Switched Network (PSN) to carry
not only voice traffic, but data and video traffic as well.
|
|
Public Key
|
The publicly known key associated with a given person's use
of a public key cryptographic system. The public key is used
for encryption.
|
|
Public Key Certificates
|
A statement, possibly on paper, but more often transmitted
electronically over an information network, that establishes
the relationship between a named individual or organization
and a specified public key, and is signed (digitally) by a
trusted authority.
|
|
Public Key Cryptography
|
An encryption method that is asymmetric, i.e., separate keys
are used for the encryption and decryption functions.
|
|
Public Switched Network (PSN)
|
The pre-Divestiture nationwide network maintained by AT&T
and the independent telephone companies which provides nationwide,
unrestricted telephone service.
|
|
Pull-Down
|
It is the amount of current needed by an inactive device
connected to the power supply.
|
|
Pull-Up
|
In this state, there is no signal activity within the device.
The inputs and outputs are not transitioning and the power
required is only due to static current.
|
|
Pulse Code Modulation (PCM)
|
The form of modulation in which the information signals
are sampled at regular intervals and a series of pulses in
coded form are transmitted representing the amplitude of the
information signal at that time.
|
|
Push Button Compilation
|
Design flow that is easy to use. Operates at the "push of
a button."
|
|
QAM
|
Quadrature Amplitude Modulation.A method of encoding digital
data in an analog signal in which each combination of phase
and amplitude represent one of sixteen four-bit patterns.
|
|
Qdesign Music Codec
|
Based in British Columbia, Qdesign developed a high quality,
streaming audio CODEC. Distributed by Apple as part of their
QuickTime media architecture, this CODEC gives excellent quality
at dialup data rates.
|
|
QDR RAM
|
Acronym for Quad Data Rate RAM. Type of memory that runs
4 times as fast as traditional RAMs. Two independent read
and write operations that occur on every rising and falling
edge of the clock.
|
|
QoS
|
Quality of Service. The set of parameters and their values
which determine the performance of a given virtual circuit.
"High QoS" usually means a guarantee of minimal (or no) data
loss, low latency, or a combination of both.
|
|
QPSK
|
QPSK - Quadrature Phase-Shift Keying. A method of modulating
digital signals using four phase states to code two digital
bits per phase shift.
|
|
Quadword
|
64 bits, sometimes knows as "QWORD"
|
|
Quantize
|
A step in the process of converting an analog signal into
a digital signal. Quantization measures a sample to determine
a representative numerical value that is then encoded. The
three steps in analog-to-digital conversion are sampling,
quantizing, and encoding.
|
|
R (Rate) Reference Point
|
Provides a non-ISDN interface between user equipment that
is not ISDN capable and ISDN adapter equipment. Examples include
RS232, V.35, and X.21.
|
|
Radio Spectrum
|
Radio spectrum consists of radio waves of different frequencies
(for example, 900 MHz, 2.4GHz, 5GHz). All radio spectra are
regulated, with some licensed and others unlicensed. This
technique sends a message as a series of computer codes. However,
since the signal is stretched out over a broad frequency band,
the receiver only needs to receive a part of the transmitted
signal to reconstruct the original message.
|
|
Radio wave
|
A combination of electric and magnetic fields varying at
a radio frequency and traveling through space at the speed
of light.
|
|
RADSL
|
Rate-adaptive ADSL - ADSL version where modems test line
at start up and adapt to fastest possible speed. All DSL modems
based on DMT are inherently rate-adaptive.
|
|
RAM
|
Random Access Memory
|
|
RAM
|
Pronounced ramm, acronym for Random Access Memory, a type
of computer memory that can be accessed randomly; that is,
any byte of memory can be accessed without touching the preceding
bytes. RAM is the most common type of memory found in computers
and other devices, such as printers. There are 2 kinds of
RAM: SRAM and DRAM.
|
|
Random access
|
Reading locations directly without having to read in a particular
sequence.
|
|
Raster Image
|
An image defined as a set of dots/pixels in a column-and-row
format. See also Bitmap.
|
|
Rasterization
|
The process of converting data and command received from
a computer into a bitmap containing an image to be printed.
|
|
Readback
|
It is the process of verifying the contents of the programmed
device against the actual programming file. It is done to
verify that the device is programmed with the correct design
file and that it is functioning properly.
|
|
RealNetworks
|
Based in Seattle, RealNetworks is the pioneer and current
market leader in streaming media technology on the Internet.
According to the company, their technology is used to deliver
content on more than 85% of all streaming media enabled Web
pages. The company derives its revenue from the delivery of
software products including authoring tools, streaming media
servers, and players; as well as streaming media delivery
services.
|
|
Real-Time
|
The actual time in which a program or event takes place.
In computing, real time refers to an operating mode under
which data is received and processed and the results returned
so quickly that the process appears instantaneous to the user.
|
|
Reed Solomon
|
Predefined decoding standards such as ATSC, IES-308 and DVB.
|
|
Reference Design
|
Free design that shows how to create an application by giving
a complete example. Customers then use this example to create
their own design.
|
|
Registry (HAVi)
|
One of the Software Elements that comprise the basic mechanisms
in HAVi to achieve interoperability. Each element provides
a certain functionality. The Software Elements that are needed
for interoperability between HAVi devices are the Messaging
System, the Registry, the Event Manager, the Resource Manager,
the Stream Manager and the DCM.
|
|
Remote Access
|
The ability of transmission points to gain access to a computer
which is at a different location.
|
|
Remote User Interface (HAVi)
|
A Remote User Interface enables a user to interact with an
application via any HAVi device in the network that has a
display. For example, a user could program the VCR in the
living room from his TV in the bedroom, again, regardless
of which manufacturer made either device.
|
|
Rendering
|
The process of translating high-level print commands into
a raster image.
|
|
Repeater
|
In a data network, a repeater can relay messages between
subnetworks that use different protocols or cable types. Hubs
can operate as repeaters by relaying messages to all connected
computers. A repeater however does not have the capability
to do the intelligent routing performed by bridges and routers,
and simply extends cabling distances by regenerating signals
to continue its propagation, usually increasing total distance
or coverage area.
|
|
Repeater
|
A repeater is a network device that repeats a signal from
one port onto the other ports to which it is connected . Repeaters
are low-level devices that amplify or regenerate weak signals.
A repeater merely passes along bits of data, even if a data
frame is corrupt. A repeater does not filter or interpret
anything; instead, it merely repeats a signal, passing all
network traffic in all directions.
|
|
Resident Font
|
Any font which is built-in to a printer by the manufacturer
as one of the standard features.
|
|
Residential Gateway, Home Gateway, Home Servers
|
A device that provides the connection between the Internet
backbone (broadband access and the home network or a home/SOHO
LAN. The gateway is dedicated to the task of a router and
generally performs protocol conversion between the Internet
backbone and the home network, data translation or conversion,
and message handling. A gateway is also considered a node
on the Internet.
|
|
Resolution
|
Number of pixels per unit of area. A display with a finer
grid contains more pixels and thus has a higher resolution,
capable of reproducing more detail in an image.
|
|
Resource Manager (HAVi)
|
The Resource Manager is a powerful feature that handles possible
resource conflicts, such as when applications want to control
the same DCM. The Resource Manager allows for the possibility
of sharing devices. The sharing function is determined by
the devices themselves. An example is a set-top box that can
simultaneously select different TV programs in the same Transport
Stream. The Resource Manager also handles conflicts that could
occur, such as when multiple applications attempt to program
a VCR (so called Scheduled Actions), or if there are conflicts
that arise due to HAVi network resource or bandwidth issues.
|
|
RF
|
Radio Frequency. A generic term for radio-based technology
and is usually referred to whenever a signal is radiated through
the air. It is the portion of the electromagnetic spectrum
with frequencies between 3 KHz and 300 GHz. This corresponds
to wavelengths between 30 kilometers and 0.3 millimeter. The
international unit for measuring frequency is Hertz (Hz),
which is equivalent to the older unit of cycles per second.
One Mega-Hertz (MHz) is one million Hertz. One Giga-Hertz
(GHz) is one billion Hertz. For reference: the standard US
electrical power frequency is 60 Hz, the AM broadcast radio
frequency band is 0.55 -1.6 MHz, the FM broadcast radio frequency
band is 88-108 MHz, and microwave ovens typically operate
at 2.45 GHz. Typically RF are frequencies from 20 kHz to 3
GHz. Literally, any and all frequencies that can be radiated
as an electromagnetic wave.
|
|
RGB
|
A type of color display output signal comprised of separately
controllable red, green, and blue signals; as opposed to composite
video, in which signals are combined prior to output. RGB
monitors typically offer higher resolution than composite
monitors.
|
|
RISC
|
Pronounced risk, acronym for Reduced Instruction Set Computer,
a type of microprocessor that recognizes a relatively limited
number of instructions.
|
|
RJ-11
|
RJ-11-Standard 4. Wire connectors for phone lines.
|
|
RJ-45
|
RJ-45-Standard 8. Wire connectors for IEEE 802.3 10/100BaseT
networks.
|
|
RJ-45
|
An "RJ-45" connector is used on Ethernet twisted pair links.
This includes the 10Base-T, 100Base-TX, 100Base-T4, 100Base-T2,
and 1000Base-T physical layer types. An RJ-45 connector has
8-pins, and may also be referred to as an "8-pin Modular Connector".
A male RJ-45 "plug" is mounted on each end of the twisted
pair cable. A female RJ-45 "jack" or "receptacle" is integrated
into the Ethernet hub or NIC.
|
|
Roaming
|
The means by which a collection of networks allow for a mobile
terminal to get connected/associated and use the services
of the network. The movement of a wireless node (portable
communications device) between two microcells, thus providing
the ability of going from (between) one access point to another
without having to re-establish the connection. Roaming usually
occurs in infrastructure networks built around multiple access
points.
|
|
ROM
|
Acronym for Read Only Memory. Used for information storage
that can be accessed but not modified.
|
|
route/routing
|
Software process of determining how to connect different
parts of the FPGA to obtain the desired functionality.
|
|
Router
|
A router is a networking device involved in protocol- independent,
LAN-to-LAN internetwork traffic management . Routers use the
Network Layer Protocol Information within each packet to "route"
it from one destination or LAN to another A router must support
Layer 3 networking protocols such as IP and IPX and routing
protocols such as RIP and OSPF. This means that a router must
be able to recognize all the different Network Layer Protocols
that may be used on the networks it is linking together. Routers
communicate with one another to determine the best route through
the complex connections of many LANs to increase speed and
cut down on network traffic. A router will decide whether
to forward a packet by looking at the protocol level addresses
(for instance, TCP/IP addresses) rather than the MAC address.
|
|
RPM
|
Acronym for Relationally Placed Macro. Design method often
used to enhance or control the performance of a circuit by
defining how the logic should be structured in an FPGA.
|
|
RS-232
|
A popular connection standard for wired serial data communications.
|
|
RSA
|
A public-key cryptographic system used for encryption and
authentication. It was invented in 1977 and named for its
inventors: Ron Rivest, Adi Shamir, and Leonard Adleman.
|
|
RSA RC-4
|
Variable key-size stream cipher algorithm designed by RSA
Inc.
|
|
RSVP
|
ReSerVation Protocol. A method being developed by the IETF
to assist in providing quality-of-service (QoS) characteristics
to communications over an IP network. The name indicates that
it allows the end-stations to reserve bandwidth on the network.
|
|
S (System) Reference Point
|
An ISDN terminal or terminal adapter interface using four
wires and alternate space inversion (ASI), sometimes referred
to as pseudo-ternary, data coding. Up to eight devices can
be connected in a multi-drop configuration to an S interface.
|
|
S (System) Reference Point (ISDN)
|
Interface between Terminal Adapters (TA) or terminal and
Network termination
|
|
SACD
|
Super Audio Compact Disc
|
|
SAR
|
Segmentation, assembly and reassembly sublayer. It converts
PDUs into appropriate lengths and formats them to fit the
payload of an ATM cell format. At the destination end-station,
the SAR extracts payloads from the cells and converts them
back into PDUs to be ultimately used by applications.
|
|
SAS
|
Subscriber Authorization System.The SAS is responsible for
generating the actual entitlement messages, following the
specifications of the encryption standard used.
|
|
Satellite
|
Direct broadcast satellites that transmit TV programs can
also provide Internet access. The satellite dish can deliver
download speed of up to 350Kbps. Upload speeds are limited
to ordinary analog modem speeds.
|
|
Scaleable Font
|
A font which can be scaled to any size, used as an alternative
term for an outline font.
|
|
Scan lines
|
The parallel lines across a video screen, along which the
scanning spot travels in painting the video information that
makes up a monitor picture. NTSC systems use 525 scan lines
to a screen; PAL systems use 625.
|
|
Scanner
|
Fundamentally, a scanner works similar to a digital camera.
An image is scanned through a lens and onto either a CMOS
sensor or a charge-coupled device (CCD), which is an array
of light-sensitive diodes. The sensor chip is typically housed
on a daughter card along with numerous A/D converters. The
CCD and its circuitry create a digital reproduction of the
image. It does this through a series of photodiodes-each containing
red, green, and blue filters-that respond to different ranges
of the optical spectrum. Once the picture is scanned the DSP
and pixel co-processor produce a JPEG (joint photographic
experts group) image that can be displayed on a screen.
|
|
SCART
|
Connector-standard used for TV/VCR devices. Also referred
to as "Euro-connector".
|
|
Scatternets (Bluetooth)
|
Comprises of multiple interconnected Piconets
|
|
schematic
|
Design entry method where the logic is described graphically
with symbols from a library.
|
|
SCPC
|
Abbreviation for Single Channel per Carrier.
|
|
Scrambling
|
Encryption of data to be transmitted for a specific service.
|
|
scratch pad
|
A temporary memory. Usually small and very fast. Used to
hold intermediate data or information during complex or large
computations.
|
|
SCSI
|
Small Computer Systems Interface
|
|
SDLC
|
Synchronous Data Link Control
|
|
SDMI
|
Secure Digital Music Initiative
|
|
SDP
|
Service Discovery Protocol
|
|
SDSL
|
Symmetric Digital Subscriber Line. Single-pair symmetric
DSL.
|
|
SDSL
|
Symmetric DSL - HDSL plus POTS over a single line.
|
|
SECA
|
Abbreviation for Societé Européene de Controle
D'Access.
|
|
SECAM format
|
SEquential Couleur A Memoire (sequential color with memory),
the French color TV system also adopted in Russia. See also
NTSC, PAL.
|
|
Secure MP3
|
MP3 files that are secure (encypted) and can be opened by
a key.
|
|
Segmented Routing
|
Ability to tap off the routing lines at predefined intervals.
|
|
SelectI/O
|
Versatile I/O's that are used to select the appropriate I/O
standard for the application. Eliminates the need for external
level tranlsation chips, reducing the number of chips and
board cost.
|
|
SelectRAM+
|
SelectRAM+ refers to Distributed and Block RAM memories that
are found in some Xilinx FPGA's.
|
|
Sequential logic
|
A flip-flop, synchronous RAM, or Latch.
|
|
Service
|
A sequence of programs under the control of a broadcaster
which can be broadcasted as part of a schedule.
|
|
Service Information
|
Service Information data is a part of all the EPG data.
|
|
Service Provider
|
A company that collects the contents from a number of program/content
providers and distributes the services to customers.
|
|
Services Gateway
|
Concept is being enabled by network operators or service
providers (SP) such as telephone operators, ISP, cable TV
operators, utilities.
|
|
Session
|
Arbitrating, establishing, and maintaining dialogs between
applications.
|
|
Session layer
|
The Session Layer provides the means for two application
layer entities to synchronize and manage their data exchange.
It basically controls the communications between applications
across a network .It sets up a communication channel between
two Application - or - Presentation layer entities for the
duration of the network transaction, manages the communication,
and terminates the connections. Testing for out-of-sequence
packets and handling two-way communication are also handled
here.
|
|
Set-top Box
|
Set Top Boxes have revolutionized home entertainment by providing
vibrant television images with crystal clear sound, along
with email, web surfing, customized information such as stock
quotes, weather and traffic updates, on-line shopping, and
video-on-demand right through a traditional television.
|
|
setup time
|
Amount of time required for data to be stable prior to the
clock for flip flops, memory or latches.
|
|
Shannon Limit
|
Refers to Shannon's noisy channel coding theorem. Which states
that given a channel, one can associate a "channel capacity"
such that there exist control codes that allow transmission
across the channel at rates less than the channel capacity
with an arbitrary small bit error rate.
|
|
SI
|
Service Information.Service Information data is a part of
all the EPG data.
|
|
SIF (Standard Interchange Format)
|
Format for exchanging video images of 240 lines with 352
pixels each for NTSC, and 288 lines by 352 pixels for PAL
and SECAM. At the nominal field rates of 60 and 50 fields/sec,
the two formats have the same data rate.
|
|
SIM
|
Subscriber Identification Modules
|
|
SIMM
|
Acronym for Single Inline Memory Module. Type of memory package
used to increase memory density on the printed circuit board.
|
|
Simulation
|
Software process of verifying the functionality of a design.
|
|
Sixel Graphics
|
A method of encoding bitmap graphics so that they may be
reliably transmitted using serial communication links.
|
|
Skew
|
The difference in arrival times of the same signal between
two or more destinations.
|
|
Slave (or Target)
|
The Slave (or Target) is the target on the PCI bus.
|
|
SLIC
|
Subscriber Loop Interface Circuit. Electronic version of
the two- to four-wire hybrid interface that supplies an analog
signal from a line card to a subscriber's phone or network
terminal equipment. It provides what is known as the BORSCHT
functions in telephony (Battery Feed, Overvoltage Protection,
Ringing, Signaling, Coding, Hybrid, and Test).
|
|
Slice
|
Two slices form a CLB within Virtex and Spartan-II families.
|
|
Slot time
|
The "slot time" is a key parameter for half-duplex Ethernet
network operation. It is defined as 512 bit times for Ethernet
networks operating at 10 and 100 Mb/s, and 4096 bit times
for Gigabit Ethernet. In order for each transmitter to reliably
detect collisions, the minimum transmission time for a complete
frame must be at least one slot time, and the time required
for collisions to propagate to all stations on the network
must be less than one slot time.
|
|
Smart Card
|
A credit card size card containing updateable magnetic or
chip memory, used for accessing encrypted TV services, e.g.
when inserted in the decoder.
|
|
Smart devices
|
Any device that contains computing intelligence. Examples
include PCs, set-top bpxes, scanners, printers, web phones,
etc.
|
|
Smart-IPtm
|
Xilinx IP that exhibits high performance, predictability,
repeatability, and flexibility.
|
|
SMS
|
Subscriber Management System (other names: CMS, Customer
Care and Billing System). The SMS is a part of a technical
chain, referred to as the entitlement control chain. The SMS
contains all customer relevant information and is responsible
for keeping track of placed orders, credit limits, invoicing
and payments, as well as the generation of reports and statistics.
When an order is placed and accepted by the SMS, the system
will support all administrative tasks regarding the customer,
e.g. invoicing, payments and business reporting.
|
|
SNMP
|
Simple Network Management Protocol. SNMP is the network management
protocol of choice for TCP/IP based Internets providing a
means to monitor and set network configuration and runtime
parameters.
|
|
SNR
|
Signal-To-Noise Ratio. A measure of the magnitude of a desired
signal relative to the magnitude of an undesired signal or
noise.
|
|
Soft Font
|
An alternative term for a downloaded font.
|
|
Software Driver
|
A generic term for a software utility such as a printer
driver.
|
|
Software Elements (HAVi)
|
Software elements are basic mechanisms in HAVi to achieve
interoperability. Each element provides a certain functionality.
The Software Elements that are needed for interoperability
between HAVi devices are the Messaging System, the Registry,
the Event Manager, the Resource Manager, the Stream Manager
and the DCM.
|
|
SOHO
|
Small Office, Home Office. Networking solutions and access
technologies for homes and offices that are not directly connected
to large corporate networks.
|
|
SOHO Routers
|
Synonomous with Home Servers and Residential Gateways. Communications
processor that connects asynchronous devices to a LAN or WAN
through network.
|
|
SONET
|
SONET stands for Synchronous Optical NETwork. The SONET format
allows different types of formats to be transmitted on one
line. SONET is a long term solution for a mid-span-meet between
vendors. The other major advantage is that SONET allows ADDING
and DROPING signals with a single multiplexer.
|
|
Spatial resolution
|
The number of points per unit length into which an image
is divided. For example, 200 dots per inch (dpi).
|
|
Spectral Compatability
|
Spectral usage of three services (POTS, UADSL & home
phoneline networking) share the same phone line by operating
at different frequencies.
|
|
Spectrum
|
A series of radiated energies arranged in order of wavelength.
The radio spectrum extends from 20 KHz upward.
|
|
Speed
|
Throughput of a laser or ink jet printer measured in p.p.m
or i.p.m.
|
|
Splitter
|
Filter to separate high-frequency ADSL and low-frequency
POTS data.Requires costly installation in home. DSL G.Lite
is splitterless, meaning it eliminates the need for an external
splitter.
|
|
Splitter / combiner
|
A transmission component which divides or sums power between
two or more ports.
|
|
Spread spectrum (SS)
|
A radio transmission technology that "spreads" the user information
over a much wider bandwidth than otherwise required in order
to gain benefits such as improved interference tolerance and
unlicensed operation. This technique was developed by the
military for use in reliable, secure, mission-critical wireless
LAN communications systems. Spread-spectrum, imparts noise-like
characteristics to an RF signal and is designed to trade off
bandwidth efficiency for reliability, integrity, and security.
In other words, more bandwidth is consumed than in the case
of narrowband transmission, but the tradeoff produces a signal
that is, in effect, louder and thus easier to detect, provided
that the receiver knows the parameters of the spread-spectrum
signal being broadcast. If a receiver is not tuned to the
right frequency, a spread-spectrum signal looks like background
noise. There are two types of spread spectrum radio: frequency
hopping and direct sequence. This communications technique
spreads a signal over a wide range of frequencies for transmission
and then de-spreads it to the original data bandwidth at the
receiver.
|
|
SRAM
|
Static Random Access Memory. SRAM consists of one flip-flop
per bit of memory. Unlike DRAMs, static RAM retains its contents
as long as power is applied. Because there is no need to refresh
the contents of memory addresses which are read, SRAM is faster
than DRAM, but it is more expensive and typically is available
in much smaller sizes than DRAM because each bit occupies
more space on the chip.
|
|
SSL
|
Secure Sockets Layer. A transport-level technology for authentication
and data encryption between a Web server and a Web browser.
|
|
SSTL
|
Acronym for Stub Series Terminated Logic. It is a high-speed
memory standard commonly used for chip to memory interface.
|
|
Stability
|
This determines whether a system exhibits oscillatory behavior
or not.
|
|
Standard Cell
|
An ASIC technology that uses building blocks that are placed
into standard size areas.
|
|
Standby State (Bluetooth)
|
Not connected to a Piconet, but occasionally monitors for
inquiries from other devices, but not synchronized with any
other devices.
|
|
State Machine
|
Design methodology that controls the output values of the
logic based on the current state and the input values.
|
|
StateCAD
|
Software used to graphically design state machines. It is
included in the Foundation ISE series software.
|
|
Static Current
|
Amount of current the device uses when powered on and inactive.
|
|
Static State or DC State
|
In this state, there are no switching signals within the
device and the inputs and outputs are not transitioning.
|
|
Static State or DC State
|
It is the device used to change the voltage levels. Example:
Device taking 220 Volts as Input and stepping down to 110
Volts as Output.
|
|
STB
|
Set-top Box
|
|
Stream Manager (HAVi)
|
One of the Software Elements that comprise the basic mechanisms
in HAVi to achieve interoperability. Each element provides
a certain functionality. The Software Elements that are needed
for interoperability between HAVi devices are the Messaging
System, the Registry, the Event Manager, the Resource Manager,
the Stream Manager and the DCM.
|
|
Streaming Audio
|
Streaming refers to the playback of audio in real-time as
it is transferred across the Internet. The advantage of this
approach is that the user does not have wait for the entire
music file to be downloaded before hearing it. The tradeoff
is that the music must be highly compressed in order to support
the access rates that most users have, typically 28.8 to 56
Kbps. This gives Net users instant gratification but relatively
poor playback quality. In addition streaming audio players
do not capture the content, so each time the clip is played
it is transferred again.
|
|
SVC
|
Stored Value Card
|
|
S-VHS or Super VHS
|
A higher-quality extension of the VHS home videotape format,
featuring higher luminance and the ability to produce better
copies.
|
|
S-video
|
Type of video signal used in the Hi8 and S-VHS videotape
formats. S-video transmits luminance and color portions separately,
using multiple wires, thus avoiding the NTSC encoding process
and its inevitable loss of picture quality. Also known as
Y/C video.
|
|
SWAP
|
Shared Wireless Access Protocol. HomeRF Specification
|
|
Switch
|
A switch is a networking device that transfers data based
on the destination addresses of the individual packets. It
selects a path or circuit for sending a unit of data to its
next destination. A switch is a simpler and faster mechanism
than a router, which requires knowledge about the network
and how to determine the route. Switches work like routers
in that they divide the network into segments, and each segment
operates without interference from local traffic to any of
the other segments.
|
|
Switching
|
The operations involved in interconnecting circuits in order
to establish communications.
|
|
Symbol Width
|
This is the number of bits per symbol.
|
|
Synchronous
|
Any operation that proceeds under control of a clock or timing
mechanism.
|
|
Synchronous Logic
|
It is the amount of resources used in the device. The resources
are: logic cells, IO cells, flip-flops and interconnect.
|
|
Synthesis
|
Process of converting HDL designs into FPGA specific features
for Place And Route (PAR).
|
|
system clock management
|
Designing to minimize the clock skew or delay to different
parts of the system, board or chip.
|
|
system gates
|
Methodology for measuring the amount of logic a device can
implement. Originally created for ASIC market.
|
|
T (Terminal) Reference Point
|
The ISDN interface between an NT1 and NT2. It is functionally
equivalent to the S interface.
|
|
T1
|
The most common data link in the U.S. communications network.
It is best known as a multiplexed carrier of 24 64-kbps voice
channels plus overhead, or 1.544 Mbps.
|
|
T3
|
U.S. digital transmission service containing 28 T1 circuits,
with a basic data rate of 44.736 Mbps.
|
|
TA (ISDN)
|
Terminal Adapter
|
|
TA (Terminal Adapter)
|
Adapts non-ISDN equipment to ISDN.A TA provides an R interface
for the non-ISDN equipment and an S/T interface for connection
to the ISDN network.
|
|
TCP
|
Transport Control Protocol.
|
|
TCP/IP
|
Transmission Control Protocol/Internet Protocol is the basic
communication protocol of the Internet. TCP/IP has two layers.
The higher layer, or Transmission Control Protocol, manages
the assembling of a message or file into smaller packets.
These packets are transmitted over the Internet and received
by a TCP layer that reassembles the packets into the original
message. The lower layer, Internet Protocol, handles the address
part of each packet so that it gets to the right destination.
Each gateway computer on the network checks this address to
see where to forward the message. Even though some packets
from the same message are routed differently than others,
they'll be reassembled at the destination.
|
|
TDM
|
Time Division Multiplexing, a type of multiplexing that combines
data streams by assigning each stream a different time slot
in a set.
|
|
TDMA
|
Time Division Multiple Access. Data multiplexing scheme used
as the basis for all digital switching networks and Central
Office switches. Each 8 kHz sample of an analog signal from
a given phone line or channel is coded into 8 bits of digital
information. These are then time multiplexed into successive
bytes of data within a digital bus or channel of data. A digital
radio technology that divides each frequency channel into
separate time slots for separate conversations or sessions.
A digital multiplexing technique whereby each signal is sent
and received at a fixed time slots in a series of time slots.
The transmitter and receiver must be time-synchronized.Most
public telephone networks typically use TDMA.
|
|
TE (ISDN)
|
Terminal Equipment
|
|
TE1 (Terminal Equipment 1)
|
ISDN terminal equipment such as ISDN telephones. These devices
interface to the ISDN network by way of an S interface.
|
|
TE2 (Terminal Equipment 2)
|
Non-ISDN terminal equipment such as personal computers. These
devices interface to a TA by way of an R interface.
|
|
Telco
|
Local telephone company.
|
|
Telephony
|
Telephone technology. The conversion of sound into electrical
signals, its transmission to another location, and its reconversion
to sound, with or without the use of connecting wires is called
telephony.
|
|
Test Bench
|
An HDL file used in simulation to test the operation of a
design.
|
|
Test vectors
|
Input signals used to test the functionality of a device.
|
|
Thoroughput
|
A measure of the volume/amount of data which can be transmitted
(typically per second) through a given communications system.
|
|
TIA TR41.5
|
Telecommunications Industry Association (TIA) TR41.5. Goal
is to create the physical layer spec for interfacing between
different WAN & home networking technologies.
|
|
Time Division Multiplexing (TDM)
|
Equipment which enables the transmitting of a number of signals
over a single common path by transmitting them sequentially
at different instants of time.
|
|
Timing Analyzer
|
Software application that determines the timing characteristics
of a design, but does not test for functionality.
|
|
timing constraints
|
Method used to increase the speed of a design by defining
the timing requirements.
|
|
Timing Simulation
|
Software process of verifying the functionality of a design
that includes the device timing characteristics.
|
|
Toner
|
A special type of ink used by copy machines and laser printers.
Toner consists of a dry, powdery substance that is electrically
charged so that it adheres to a drum, plate, or piece of paper
charged with the opposite polarity.
|
|
Toner Cartridge
|
A cartridge or cassette which holds toner for ease of loading
into a printer.
|
|
TQFP
|
Acronym for Thin Quad Flat Pack. Low profile, surface mount
package.
|
|
TRACE
|
Xilinx application in Foundation ISE, Foundation and Alliance
that determines how fast a design can run.
|
|
Transceiver
|
A combination radio transmitter and receiver.
|
|
Transponder
|
A satellite is divided up in parts called transponders. A
transponder is one distribution channel of the satellite.
Each transponder can be used for distribution of several programs.
|
|
transport
|
Guarantees reliable delivery between end stations
|
|
Transport layer
|
The Transport Layer is generally called the higher layer
as to how traffic is moved. It ensures the performance of
the lower 3 OSI layers. The Transport Layer forms the interface
between the higher application-oriented layers and underlying
network-dependent protocol layers. It provides the session
layer with reliable message transfer facilities. It offers
transparent transfer of data between end stations or edge
nodes, error recovery, and flow control.
|
|
Triple-DES
|
Reading locations directly without having to read in a particular
sequence.
|
|
tristate buffer
|
see 3-state
|
|
Truck rolls
|
The process of having support people from utilities, industries
visit the home to deploy services such as a residential gateway,
dgital modems, meter reading, etc. These truck rolls are usually
very costly.
|
|
True Black
|
Black produced by a separate black ink rather than the 'composite
black' produced from a mixture of cyan, magenta and yellow.
See also Composite Black.
|
|
True DualPort RAMTM
|
See Dual Port RAM
|
|
TrueType
|
A font definition format for outline fonts which is used
by Microsoft Windows for the creation of screen fonts and
downloaded fonts.
|
|
TTL
|
Acronym for Transistor Transistor Logic. The 7400 series
of logic fabricated with bipolar transistors.
|
|
Turnaround cycle
|
The turnaround cycle is a "dead" bus cycle to prevent bus
contention.
|
|
TwinVQ (Transform-domain Weighted
Interleave Vector Quantization)
|
Developed by NTT Human Interface Labs in Japan, this new
compression technology is called Transform-Domain Weighted
Interleave Vector Quantization, or TwinVQ. This compression
technology, targeted at download applications, was originally
developed by Yamaha and has been incorporated, along with
AAC, into the MPEG-4 specification. The underlying algorithms
are significantly different the algorithms used in MPEG layer
III.
|
|
Twisted Pair Cable
|
There are 3 major types of Twisted Pair Cables ( Shielded,
Unshielded, and Screen Twisted). In Twisted Pair cables, pairs
of wires are twisted around one another. Each pair consists
of two insulated copper wires twisted together. The wire pairs
are twisted because it helps reduce crosstalk and noise susceptibility.
High quality twisted pair cables have about 1 to 3 twists
per inch. Twisted pair cables are used with the following
Ethernet physical layers: 10Base-T, 100Base-TX, 100Base-T2,
100Base-T4, and 1000Base-T.
|
|
U (User) Reference Point
|
The interface between the ISDN customer premises equipment
and the public ISDN network. This interface defines a point
to point connection using a single twisted pair and 2B1Q data
coding.
|
|
UADSL
|
Universal ADSL
|
|
UART
|
Universal Asynchronous Receiver Transmitter. Serial data
protocol that transfers data at set data (baud) rates. These
data rates are based on transitions of the data at set time
periods; no clock is transmitted between the transmitter and
receiver.
|
|
UDP
|
User Datagram Protocol. The connectionless protocol within
TCP/IP that corresponds to the transport layer in the ISO/OSI
model. UDP converts data messages generated by an application
into packets to be sent over IP, but does not verify that
messages have been delivered correctly.
|
|
UNH - IOL
|
University of New Hampshire - InterOperability Lab well known
for its work in verifying interoperability between classes
of networking devices.
|
|
Universal ADSL
|
Another name for G.lite. Also the name of the working group
that developed it.
|
|
Unshielded twisted pair
|
Unshielded, is the the first type of a twisted pair Ethernet
cable. There are different types of UTP available(Cat 3, 4,
5, 5e, 6, and 7) . Category 1 & Category 2 are not suitable
for use with Ethernet Transmission frequency rate is what
differentiate them.
|
|
UPnP
|
Universal Plug and Play. A cross-industry initiative to simplify
the interconnection of PCs, appliances, networks and services
by extending Plug and Play to include networks, move to a
peer model, and incorporate capabilities discovery. Universal
Plug and Play will discover devices on a network and also
enumerate each device's unique characteristics, including
communications protocols.
|
|
Upstream
|
Data transmitted from the modem to the Internet.
|
|
USB
|
Universal Serial Bus. A bidirectional, isochronous, dynamically
attachable serial interface for adding peripheral devices
such as game controllers, serial and parallel ports, and input
devices on a single bus. (This serial protocol runs at 1-12
Mbps.) A newer style of bus and connector for attaching peripheral
devices such as keyboards, scanners, cameras or speakers to
a PC. The connector on the back of the PC looks like a flat
telephone jack, and when you plug in a new USB device, most
PCs running Windows* 98 can detect it automatically and begin
using it without the need to reboot the system (plug and play).
|
|
USB
|
Universal Serial Bus - Standard for serial transmission between
a computer and peripherals.Supports up to 12 Mbps and plug-and-play.
|
|
USB
|
Acronym for Universal Serial Bus. Perhipheral standard for
serial transmission supporting plug-and-play.
|
|
Utilization
|
Percentage of resources used in the device. The resources
are: logic cells, block RAM, IO blocks, flip-flops and interconnect.
|
|
UTOPIA
|
Universal Test & Operations Interface for ATM - Refers
to an electrical interface between the sublayers of the PHY
layer.
|
|
UTP
|
Unshielded Twisted Pair
|
|
V Reference Point
|
Proprietary interface within central office used to connect
the line cards to the ISDN switch.
|
|
V.90 Modem - Analog Phoneline
|
V.90 modem, 56K modem is designed to operate with dial-up
telephone lines worldwide. It supports high-speed analog data,
high speed fax & audio/voice operation. This integrated
modem is host controlled and helps reduce chip count since
there is no separate microcontroller. Data speeds up to 56Kbps
from a digitally connected central site modem - V.90 enabled.
Data can be sent upstream at speeds up to 33.6Kbps.
|
|
Variable-bit codec
|
Variable-bit codec allows the user to determine the sampling
rate for encoded audio. Higher sampling rates means that the
audio maintains better fidelity to the original but results
in less compression. Better the quality, larger are the resulting
files & vice versa. For most consumers MP3 files encoded
at reasonable rates (96kbps or 120kbps) are distinguishable
from CDs.
|
|
Variance
|
In video and imaging applications, this refers to how much
a pixel changes.
|
|
VDSL
|
Very high data rate DSL - 12.9-52.8 Mbps at shorter distances.
|
|
Vector Graphics
|
A method of describing lines and curves as mathematical
equations or vectors.
|
|
vector-based routing
|
Ability to maintain consistent performance for a block of
logic as it is moved to different locations within Xilinx
FPGA's.
|
|
verification
|
Part of the design process that checks to make sure the design
operates as the designer intended. Simulation is a type of
verification.
|
|
Verilog
|
A design language that designers use when creating FPGA or
ASIC designs.
|
|
VESA
|
Video Experts Standards Association
|
|
VESA
|
VESA (Video Electronics Standards Association) Local Bus
(sometimes called the VESA VL bus) is a standard interface
between your computer and its expansion slots that provides
faster data flow between the devices controlled by the expansion
cards and your computer's microprocessor.
|
|
VHDL
|
Acronym for VHSIC Hardware Description Language (VHSIC is
an acronym for Very High-Speed Integrated Circuits). A design
language that designers use when creating FPGA or ASIC designs.
|
|
VITAL
|
Acronym for VHDL Initiative Toward ASIC Libraries. This VHDL
industry standard defines how simulation models should be
created to allow simulators to work consistently. Xilinx includes
VITAL libaries in the software tools.
|
|
VM
|
Virtual Machine
|
|
VOD
|
Video On Demand. Term properly describing movie service,
but now generally referring to all types of on-demand services
where viewers are able to order and see a given program of
an individual basis at the time specified.
|
|
VoDSL
|
Voice over Digital Subscriber Line
|
|
VoIP
|
Voice over Internet Protocol
|
|
VPN
|
Virtual Private Network. A network service offered by public
carriers in which the customer is provided a network that
in many ways appears as if it is a private network (customer-unique
addressing, network management capabilities, dynamic reconfiguration,
etc.) but which, in fact, is provided over the carrier's public
network facilities. It hence enables IP traffic to travel
securely over a public TCP/IP network by encrypting all traffic
from one network to another. A VPN uses "tunneling" to encrypt
all information at the IP level.
|
|
VToA
|
Voice Telephony over ATM. Specified by the ATM Forum.
|
|
Wait State
|
The wait state is a bus cycle where it is possible to transfer
data, but no data transfer occurs.
|
|
WAN
|
Wide area network. A communications network that connects
devices over wide geographically separated areas, usually
encompassing different metropolitan areas. Such networks require
public rights-of-way and operate over long distances. Large
network formed by bridging smaller LANs or using dial-up lines.
WANs can even span the globe.
|
|
Warm-up Time
|
The time taken after switching on for a printer to achieve
a state where it is ready to print. The warm-up time is normally
dictated by the time taken to heat up the fuser to its operating
temperature.
|
|
Wavelength
|
The distance that an electromagnetic wave travels in one
complete cycle.
|
|
Web Access APIs
|
Web Access APIs are API's that can be implemented by HAVi
devices to enable any HAVi device in the home (such as PCs
or internet-enabled TVs) to have access to the internet, without
requiring the device to have an IP stack itself. Through these
APIs, the Internet protocols such as HTTP and FTP are encapsulated
and delivered to these HAVi devices.
|
|
Web phone
|
A telephone-like device optimized for internet telephony
and web browsing.
|
|
Web Tablet, Web Pad, Fridge Pad
|
Wireless, portable, low-cost, easy to use, tablet-shaped
consumer-focussed information appliance with a touch-screen
user interface and a browser-based interface to simplify and
enhance the internet experience.
|
|
Web terminals
|
Stand-alone devices used primarily for web browsing and email.
|
|
WECA
|
Wireless Ethernet Compatability Alliance
|
|
WEP
|
Wired Equivalent Privacy - Privacy feature in IEEE 802.11
that uses the RC4 PRNG algorithm from RSA Data Security.
|
|
White goods
|
Networked Dishwashers, Washing Machines, Dryers, Microwaves,
Ovens, Toasters
|
|
Windows Media Player
|
Multimedia platform that comes with Microsoft Windows. It
is the default front end for playing audio & video files.
|
|
Wireless
|
Communications that take place without the use of interconnecting
wires or cables, using radio waves, microwave, or infrared.
The term refers to a broad range of technologies that provide
mobile communications for university, home or office, and
"in-building wireless" for extended mobility around the work
area, campus, or business complex. It is also includes "cellular"
communication used for in- or out-of-building mobility services.
|
|
Wireless Ethernet
|
While "Ethernet" is a wired system by definition, wireless
Ethernet describes for CSMA/CA wireless LAN's, since their
operation has a great deal in common and they are typically
integrated easily.
|
|
Wireless LAN
|
A wireless local area network (LAN) is a flexible-data communications
system implemented as an extension to or as an alternative
for, a wired LAN. Using radio frequency (RF) technology, wireless
LANs transmit and receive data over the air, minimizing the
need for wired connections. Thus, wireless LANs combine data
connectivity with user mobility. A short range computer to
computer wireless data communications network.
|
|
Wireless Network Interface Card (NIC)
|
The wireless-network interface card that typically uses DSSS
physical layer and CSMA/CA medium access control.
|
|
Wireless Node
|
A user computer with a wireless-network interface card (adapter).
|
|
WLANA
|
Wireless LAN Association
|
|
WLIF
|
Wireless LAN Interoperability Forum
|
|
WMA (Windows Media Audio)
|
Part of Microsoft's Windows Media Technologies, which combines
Video for Windows, ActiveMovie, and NetShow into a unified
architecture. A key feature of this architecture is that it
automatically downloads CODECs for new formats from the Internet
as needed.
|
|
W-OFDM
|
Wideband OFDM.
|
|
Workgroup Printer
|
A medium-sized laser printer designed to handle the printing
requirements of several users, normally attached to a LAN
or multi-user computer.
|
|
WPS
|
Windows Print System: the scheme supported by Windows 95
in which the operating system spools data from an application
in Enhanced Metafile Format (EMF), instead of raw printer
data. The spooler interprets the data in the background and
then passes appropriate commands to the printer. Like with
GDI, all the processing is done on the PC.
|
|
X.25
|
An X.25 network is one in which packets of data are moved
to their destination along routes determined by network conditions
as perceived by routers, and reassembled in the right order
at the ultimate destination.
|
|
X-10
|
X-10 is a communications protocol for remote control of electrical
devices. It is designed for communications between X10 transmitters
and X10 receivers which communicate on standard household
wiring. X-10 is a powerline carrier protocol that allows compatible
devices throughout the home to communicate with each other
via the existing 110V wiring in the house. It can make a controlled
network of different devices connected together. The X-10
powerline protocol transmits binary data using Amplitude Modulation.
|
|
xDSL
|
The general class of Digital Subscriber Line (DSL) technologies.
|
|
XML
|
Extensible Markup Language. A formal specification of the
World Wide Web Consortium (W3C).
|
|
YCbCr
|
The three components of component video -- with Y for luma
and Cb and Cr for different chroma components.
|
|
YUV color system
|
A color-encoding scheme for natural pictures in which the
luminance and chrominance are separate. The human eye is less
sensitive to color variations than to intensity variations,
so YUV allows the encoding of luminance (Y) information at
full bandwidth and chrominance (UV) information at half bandwidth.
|
|
Z Transform
|
An important transform used in the analysis of digital filter
response and stability.
|
|
ZBT
|
Zero Bus Turnaround (ZBT) is a synchronous SRAM architecture
optimized for networking and telecommunications applications.
It can increase the internal bandwidth of a switch fabric
when compared to standard SyncBurst SRAM. ZBT SRAMs became
the de facto industry standard for these applications when
they were introduced, much like Synchronous Burst SRAMs are
the industry standard in the PC cache market.
The ZBT architecture is optimized for switching and other
applications with highly random READs and WRITEs. ZBT SRAMs
eliminate all idle cycles when turning the data bus around
from a WRITE operation to a READ operation (or vice versa).
This feature results in dramatic performance improvements
in systems that have such traffic patterns, i.e., frequent
and random read and write access to the SRAM.
|
|
ZBT RAM
|
Acronym for Zero Bus Turnaround. Type of SRAM that can read
or write every clock cycle for 100 percent bus efficiency.
Optimized for networking and telecommunications applications.
|
