Peripheral Component Interface
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A Brief Description of the PCI-X [Peripheral Component Interface] Bus;
The Peripheral Component Interface [PCI-X] addendum is an enhancement to the current 64 bit 66MHz PCI bus specification. The minimum clock speed for PCI-X is 66MHz [PCI-X 66]. Additional bus speeds include: PCI-X 133, PCI-X 266 and PCI-X 533 providing up to 4.3GBps [PCI-X 1066 in the works]. PCI-X is backwards compatible with PCI; of course none of the enhancements would be available and the best speed would revert to 66MHz. PCI-X provides for the same card form factor, pin-outs, connector, bus widths, and protocols. Many of the changes relate to bus operation, wait states and protocol enhancements, which is not covered here. PCI-X still supports either 32 bit or 64 bit bus widths. The DC switching Specifications look the same for PCI and PCI-X. PCI-X does have a higher output AC driver current than PCI. The PCI-X enhancement was never introduced into the Personal Computer market, although it did show up in the [higher cost] server market.
The PCI spec defines the Electrical requirements for the interface.
No bus terminations are specified, the bus relies on signal
reflection to active level threshold. The PCI bus operates either
synchronously or asynchronously with the "mother Board bus rate.
While operating asynchronously the bus will operate at any frequency
from 66MHz down to (and including) 0Hz. Flow control is added to
allow the bus to operate with slower devices on the bus, allowing the
bus to operate at their speed. PCI is an unterminated bus, the signal
relay on signal reflections to attain there final value. The PCI
specification has been port-ed to a number of other form factors.
These include:
The Time Multiplexed Address and Data bus may exist as either 0 to 31
bits (32bits) or 0 to 63 bits (64bits) using the 64 bit expansion
bus. Both the Address and Data line use the same bus, Address first
then Data. 32 bit PCI may also use 64 bit addressing by using two
address cycles; termed Dual Address Cycles (DAC), the low order
address is sent first. Additional control bits are utilized once the
bus is increased to 64 bits. |
The PCI bus [or PCI X bus] doesn't use Glue logic ICs, being
developed as a single chip interface bus.
So signal chip solutions or ASIC parts are the only PCI chips. PCI IC
manufacturers are listed below.
PCI is a CMOS bus, with no current flowing in the static state. The +5
volt interface uses standard TTL switching levels;
VIH = 2v, VOH = 2.4v. The +3.3
volt interface uses VIH = 1.65v, VOH = 2.97v
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Altera {PCI Cores}
Cirrus Logic {PCI-Disk Controller ICs}
Infineon Technologies {PC Chips-DRAM Controller ICs}
Marvell {PCI chip set Manufacturer}
PLX Technology Inc. {133MHz PCI-X-to-PCI-X [P2P] bridge Chip}
QLogic {PCI ICs - SBus}
Silicon Image Inc {Ultra ATA/100 PCI to ATA Host Controler ICs}
Texas Instruments {PCI Bridges-Controller ICs}
Xilinx {FPGA Core; PCI-X for 64-bit designs running at speeds up to 133 MHz}
PICMG: PCI Industrial Computer Manufacturers Group [www.picmg.org]
PCISIG: Peripheral Component Interconnect - Special Interest Group [www.pcisig.com]
PCI Local Bus Specification:
PCI version 1.0 was developed by Intel in 1991 but not released by
a Standards body.
PCI revision 2.0; released in 1993; 32-bit, 33MHz bus.
PCI revision 2.1; released in 1995; 32-bit, 33MHz / 64-bit, 66MHz,
Universal PCI for 3.3v or 5v cards
PCI revision 2.2; released 1998; minor clarifications /
enhancements.
PCI revision 2.3; released in 2002; removed 5v only cards
PCI revision 3.0; released in 20xx; removed 5 volt interfaces
altogether.
PCI in other Form Factors:
PCI-X Addendum to PCI Local Bus Specification (Ver 1.0)
Mini PCI Bus Specification (Ver 1.0)
Small PCI Specification (Ver 1.5a)
PCI-to-PCI Bridge Specification (Ver 1.1)
PCI Model Design Guide (Ver 1.1)
PCI Bus Power Management Specification (Ver 1.1)
PCI Hot-Plug Specification (Ver 1.0)
PCI Bios Specification (Ver 2.1)
HiRelPCI An Extensible High Reliability Extended PCI Bus (Draft
0.65)
PXI Specification {Ver 1.0}
PISA Bus (Ver 1.8)
PISA-2 (Ver 1.2) PISA Back Plane with 1 PISA and 1 ISA Slot
CompactPCI Specification (Ver 2.0 R2.1 - Short Form)
AVX {Connector Manufacturer}
FCI {Connector
Manufacturer}
Meritec {PCI Cable Assemblies}
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