Peripheral Component Interconnect

Peripheral Component Interconnect

Peripheral Component Interconnect (PCI) is a computer bus standard that allows the connection of peripheral devices to a computer's motherboard. It was first introduced by Intel in 1993 and has since become the most widely used bus standard in personal computers.

History

The development of PCI was driven by the need for a faster and more versatile bus architecture to replace the aging Industry Standard Architecture (ISA) and Micro Channel Architecture (MCA) standards. Intel, along with other industry leaders, formed the PCI Special Interest Group (PCI-SIG) to develop the new standard.

Architecture

PCI is a parallel bus architecture that uses a shared bus topology. It consists of a set of electrical and mechanical specifications that define the physical and electrical characteristics of the bus. The bus operates at various speeds, ranging from 33 MHz to 133 MHz, depending on the version.

Features

PCI offers several features that make it a popular choice for connecting peripheral devices. These include:

- **Plug and Play**: PCI devices can be hot-swapped, meaning they can be connected or disconnected from the bus without having to power down the computer.

- **Bus mastering**: PCI allows devices to take control of the bus and perform direct memory access (DMA) transfers, reducing the load on the CPU.

- **Multiple bus support**: PCI supports multiple buses, allowing for the expansion of the system with additional PCI buses.

- **Shared interrupts**: PCI devices can share interrupts, reducing the number of interrupts required by the system.

Variants

Over the years, several variants of PCI have been developed to meet the evolving needs of the industry. These include:

- **PCI-X**: An extension of the PCI standard that increases the bus speed and adds support for 64-bit addressing.

- **PCI Express**: A high-speed serial bus standard that provides faster data transfer rates and improved scalability compared to traditional PCI.

Usage

PCI is used to connect a wide range of peripheral devices to a computer, including network cards, sound cards, graphics cards, and storage devices. It provides a standardized interface that allows these devices to communicate with the CPU and other components of the system.

References

- PCI-SIG Official Website

- Peripheral Component Interconnect - Wikipedia

See Also

- Motherboard

- Industry Standard Architecture

- Micro Channel Architecture