Storage Register

Features

Family Support

ACT 1, ACT 2, ACT 3, 3200DX, MX, SX, SX-A, eX, 500K, PA, Axcelerator, ProASIC3/E, Fusion

Description

Storage registers have a parallel-in/parallel-out (PIPO) architecture. The registers are WIDTH bits. They are clocked on the rising (RISE) or falling (FALL) edge of the clock Clock (CLK_EDGE).

The Clear signal (CLR_POLARITY), active high or low, provides an asynchronous reset of the registers to “000…0”. You may choose to not implement the reset function.

The Enable signal (EN_POLARITY), active high or low, provides a synchronous load enable operation with respect to the Clock signal. You can choose to not implement this function. Storage registers are then loaded with a new value every clock cycle.

The Set signal, active high or low, provides an asynchronous set of the registers to "1111...1".  You may choose not to implement the Set function.

Port Description

Port Name

Size

Type

Req./Opt.

Function

Data

WIDTH

input

Req.

Register load input

Aclr

1

input

Opt.

Asynchronous register reset

Enable

1

input

Opt.

Synchronous Parallel load enable

Clock

1

input

Req.

Clock

Q

WIDTH

output

Req.

Register output bus

Parameter Description

Parameter

Family

Value

Function

WIDTH

500K, PA

1-512

Word length of Data and Q

All others

1-99

CLR_POLARITY

All

0 1 2

Aclr can be active low, active high, or not used

EN_POLARITY

All

0 1 2

Enable can be active low or active high

CLK_EDGE

All

RISE FALL

Clock can be rising or falling

Fan-in Control Parameters

Parameter

Value

CLR_FANIN

AUTO MANUAL

CLR_VAL

<val> [default value for AUTO is 8, 1 for MANUAL]

EN_FANIN

AUTO MANUAL

EN_VAL

<val> [default value for AUTO is 6, 1 for MANUAL]

CLK_FANIN

AUTO MANUAL

CLK_VAL

<val> [default value for AUTO is 8, 1 for MANUAL]

Implementation Parameters

Parameter

Value

Description

LPMTYPE

LPM_DFF

Register category

LPM_HINT

PIPO

Parallel-in/Parallel-out

Functional Description A

Data

Aclr

Enable

Clock

Q

X

0

X

X

0’s

X

1

X

Ø

Qn

X

1

0

¦

Qn

m

1

1

¦

Qn+1 = m

A. Assume Aclr is active low, Enable is active high, Clock is rising (edge-triggered).