CardBus
Passive-Backplane PCI CompactPCI IndustrialPCI PCI Mezzanine Card (PMC) Small PCI (SPCI) |
CardBus
Differences between CardBus and PCI are driven first by the PCMCIA mechanical environment, and next by the need to make CardBus sockets backward compatible with PCMCIA R2.x cards. PCI compliant devices are not automatically compliant with CardBus. The table below summarizes the basic differences between PCI and CardBus.
An organization known as Yenta has been formed to help insure interoperability among chip, card, system and software manufacturers of CardBus products. For additional information you might try the following: PCMCIA Headquarters
PCMCIA European Chapter
Yenta
More information on Xilinx and PCMCIA. Passive-Backplane PCI
The PBPCI specification was designed to allow use of existing desktop ISA and PCI add-in boards in the backplane without modification. The physical specification allows both ISA and either 32- or 64-bit PCI connectors to exist on one side of the board. Backplanes with a dual-bus CPU connector, 1 to 4 PCI connectors and 6 to 15 ISA connectors are available today. The signals on the PCI interface have the same pin numbers as a PCI expansion slot. In addition, separate REQ# and GNT# lines are provided for each PCI slot to support up to four bus masters in one system. Because PBPCI allows up to 9-in. traces on PCI signals, a PBPCI CPU must provide a separate clock driver for each PCI slot in order to meet the 2-nsec clock-skew limit. For more information regarding CompactPCI or to order a complete specification, contact the PCI Industrial Computer Manufacturers Group at: PICMG
CompactPCI
CompactPCI cards are based on the 3U and 6U Eurocard industry standard formats. They use high-performance shielded, 2-mm-pitch pin-and-socket connectors that have lower capacitance than desktop-style PCI edge connectors. CompactPCI also specifies the use of 10-ohm stub-termination resistors on signal lines that reduce the effect of board circuits on bus loading. These differences allow a maximum of eight cards to be put into a single CompactPCI backplane without the need for a PCI-to-PCI bridge. Use of bridges, however, allows up to 256 CompactPCI backplanes in a single system. CompactPCI defines some additional signals on top of the PCI specification to enhance system operation. These signals provide push putton reset, power supply status, System Slot identification and legacy IDE interrupt support features. The standard has provision for 32- and 64-bit interfaces, as well as 5V and 3.3V signalling. Provision for hat-swapping is also provided, but many things need to be worked out before that becomes a reality. A 32-bit mezzanine version and form factor is also defined for space constrained embedded applications. For more information regarding CompactPCI or to order a complete specification, contact the PCI Industrial Computer Manufacturers Group (PICMG). Also see the CompactPCI home page at: EMAIL: info@compactpci.com
IndustrialPCI
For more information regarding IPCI or to obtain a complete specification, contact the Standard Industrial PC Systems manufacturers group at: SiPS e.V.
PCI Mezzanine Card (PMC)
For additional information you might try the following: VITA at 602-951-8866
Small PCI (SPCI)
There are many physical similarities between SPCI and PCMCIA cards. Both have the exact same footprint, however SPCI uses a 108-pin connector versus PCMCIA's 68. Two SPCI card thicknesses are defined; Type A cards are 5.0 mm thick and Type B cards are 10.5 mm, corresponding to PCMCIA's Type II and III cards, respectively. These tight form factors will benefit from smaller device packaging such as the TQ/VQFPs available from Xilinx. The specification states that its intent "is to define cards that are installed at the point of manufacture" and hence do not include descriptions for protective covers. But since the specification indicates that covers are not prohibited, it remains to see whether or not SPCI will compete directly with PCMCIA or CardBus as a user-accesible form of system expansion. SPCI supports 5-Volt, 3.3-Volt and universal cards through a keyed connector scheme. Keying provisions have also been made to exclude PCMCIA, JEIDA and DRAM cards without damaging connector interfaces. Revision 1.0 of the specification was released by
the PCI-SIG on May 1, 1996, and may be obtained from that organization. All
Xilinx PCI compliant devices can be used in SPCI applications.
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