Peripheral Component Interconnect

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Related to Peripheral Component Interconnect: Peripheral Component Interconnect Express

peripheral component interconnect

[pə‚rif·ə·rəl kəm‚pō·nənt ′in·tər·‚kə·nek]
(computer science)
A bus standard for connecting additional input/output devices (such as graphics or modem cards) to a personal computer. Abbreviated PCI.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Peripheral Component Interconnect

(PCI) A standard for connecting peripherals to a personal computer, designed by Intel and released around Autumn 1993. PCI is supported by most major manufacturers including Apple Computer. It is technically far superior to VESA's local bus. It runs at 20 - 33 MHz and carries 32 bits at a time over a 124-pin connector or 64 bits over a 188-pin connector. An address is sent in one cycle followed by one word of data (or several in burst mode).

PCI is used in systems based on Pentium, Pentium Pro, AMD 5x86, AMD K5 and AMD K6 processors, in some DEC Alpha and PowerPC systems, and probably Cyrix 586 and Cyrix 686 systems. However, it is processor independent and so can work with other processor architectures as well.

Technically, PCI is not a bus but a bridge or mezzanine. It includes buffers to decouple the CPU from relatively slow peripherals and allow them to operate asynchronously.
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(1) (Payment Card Industry) See PCI DSS.

(2) (Peripheral Component Interconnect) A hardware interface for connecting peripheral devices to a computer. Introduced in 1993 and designed by Intel, Compaq and Digital Equipment, PCI superseded the ISA interface. PCI was widely used before it was superseded by PCI Express a decade later.

When first deployed, personal computers had several PCI slots; however, as time passed more computers used control circuits built into the motherboard chipsets, and the need for multiple slots diminished. Motherboards would later have only one PCI slot and an AGP slot for graphics. Eventually, PCI Express (PCIe) became the primary hardware interface for personal computers. See PCI Express and ISA.

PCI Made Life a Lot Easier
PCI eliminated conflicts that plagued the earlier ISA bus, which required an interrupt request (IRQ) number to be assigned to each ISA card. In contrast, the PCI bus architecture shares IRQs. Motherboards with both ISA and PCI were made for several years, and if there was only one IRQ left after the rest were assigned to ISA cards, all PCI devices could share it.

PCI Slots
PCI supports bus mastering, 32 and 64-bit data paths and runs at 33 or 66 MHz. The slot quantity is based on 10 electrical loads that deal with inductance and capacitance. The PCI chipset uses 3, motherboard controllers use 1, and plug-in cards use 1.5. For more slots, two PCI buses can be bridged. To compare data rates, see PCI-SIG. See bus mastering, PCI-X, Concurrent PCI, CompactPCI, PXI, PC data buses, PICMG and Sebring ring.

PCI Slots Are Not PCI Express (PCIe)
PCI sockets are not the same as PCIe. In addition, PCIe slots come in different sizes.

How PCI Is Connected
This illustration shows how the CPU, memory and peripherals are interconnected in a PC. Today's motherboards may not have any PCI slots. See PCI Express.
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References in periodicals archive ?
Development of the current peripheral component interconnect (PCI) interconnect was started in 1992 and introduced with the first Pentium microprocessors in 1995.
The software also now supports PC-CamLink, the developer's digital peripheral component interconnect frame grabber.
Offering support for the Linux operating system, the new product consists of a peripheral component interconnect (PCI) ADSL network interface card which is based on one of Agere's digital signal processor client access chips.
PCI, or 32-bit peripheral component interconnect, have replaced the older 8-and 16-bit ISA, or industry standard architecture, expansion slots.
Conexant's first LANfinity products, introduced in October 1998, have used a high-performance Peripheral Component Interconnect media access controller.
PCI-X, the proposed high- performance extension of the PCI local bus specification aimed at workstations and servers, is currently under development by the PCI-X working group, part of the Peripheral Component Interconnect Special Inte rest Group, based in Hillsboro, Oregon.
Tsunami Conventional computers are built around bus architectures, such as Intel's Peripheral Component Interconnect (PCI) and Accelerated Graphics Port (AGP).
The field-programmable gate arrays (FPGA) are loaded from a programmable read-only memory (PROM), which is updated over the peripheral component interconnect (PCI) interface.
Today, VESA is working on an updated local bus specification to compete with the Peripheral Component Interconnect (PCI).
It is expected to gradually replace the existing peripheral component interconnect (PCI) shared-bus approach used in most of current personal computers and servers.
* Multiple high-performance onboard I/O capabilities with 1 Peripheral Component Interconnect Express x16 slot for a higher-end graphics card, 1 Peripheral Component Interconnect Express x4 slot, 2 Peripheral Component Interconnect 32/33 slots and 8 high-speed USB 2.0 ports.
With multiple PCI Express bus, AGP bus (Accelerated Graphic Port) and PCI bus (Peripheral Component Interconnect) comp atible cards, Verto's broad product line provides an ideal graphic card solution for amateurs to enthusiasts.

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