The PCI refers to the computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification, or an expansion card that fits into a PCI slot. ( A,B : ports and sockets of a motherboard )
Typically, PCI cards used in the expansion slots of a PC include network cards, sound cards, modems, extra ports such as USB or SATA, TV tuner and disk controllers.
The common specifications of PCI ports are:
- 32 or 64 bit bus-width
- 33.33 or 66.67 MHz synchronous clock
- transfer rate of 133 MB/s for 32-bit
- 32- or 64-bit memory address space (4 GB or 16 EB)
- 5-volt signaling