PCI BUS
- 1. BY TEAM 1: PERIPHERAL COMPONENT INTERCONNECT (PCI) BUS
- 2. INTRODUCTION: ❖ Peripheral Component Interconnect (PCI) is a local compute bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. ❖ The PCI bus is a good example of a system bus that grew out of the need for standarization. ❖ An important feature that the PCI pioneered is a plug and play capability for connection I/O devices.
- 3. ❖ PCI slots are utilized to install sound cards, Ethernet and remote cards and presently strong state drives utilizing NVMe innovation to supply SSD drive speeds that are numerous times speedier than SATA SSD speeds. PCI openings too permit discrete design cards to be included to a computer as well. ❖ PCI openings (and their variations) permit you to include expansion cards to a motherboard. The extension cards increment the machines capabilities past what the motherboard may create alone, such as: upgraded illustrations, extended sound, expanded USB and difficult drive controller, and extra arrange interface options, to title a couple of.
- 4. HISTORY OF PCI BUS: ❖ Work on PCI began at the Intel Architecture Labs (IAL, also Architecture Development Lab) c. 1990. A team of primarily IAL engineers defined the architecture and developed a proof of concept chipset and platform (Saturn) partnering with teams in the company's desktop PC systems and core logic product organizations. ❖ PCI was immediately put to use in servers, replacing Micro Channel architecture (MCA) and Extended Industry Standard Architecture (EISA) as the server expansion bus of choice. In mainstream PCs, PCI was slower to replace VLB, and did not gain significant market penetration until late 1994 in second- generation Pentium PCs. By 1996, VLB was all but extinct, and manufacturers had adopted PCI even for Intel 80486 (486) computers.
- 8. Device Configuration When an I/O device is connected to a computer, several actions are needed to configure both the device and the software that communicates with it. The software needs to know the address of the device and also the device characteristics , such as the speed of the transmission link etc; The PCI simplifies this process by incorporating a small Configuration ROM memory that stores information about that device in each I/O device interface.
- 9. Device Configuration in PCI Bus ❖ The PCI has a configuration ROM that stores information about the device. ❖ The configuration ROMs of all devices are accessible in the Configuration Address-Space. ❖ The PCI initialization software reads these ROMs whenever the system is powered up or reset. ❖ In each case, it determines whether the device is a printer, a keyboard or an Ethernet interface. ❖ Devices are assigned addresses during the Initialization process. ❖ Hence Devices cannot be accessed based on their address during the configuration process.
- 10. ❖ Each device has an input signal called Initialization Device Select , IDSEL# . ❖ IDSEL# pin of each device is connected to one of the upper 21 address lines(AD11 to AD31) ❖ During configuration operation , ➢ A configuration command and an address is issued. ➢ The corresponding AD line is set to 1 and the remaining 20 lines are set to 0. ❖ The lower address lines , (AD10 to AD00) are used to specify the type of operation and to access the contents of Configuration ROM.
- 11. ❖ The configuration software scans all 21 locations. ❖ Each device may request an address in the I/O space or Memory space. ❖ The PCI Bus has four interrupt request lines. ❖ The software instructs the device as to which of these lines it can use to request an interrupt. This process relieves the user from having to be involved in the configuration process.The user simply plugs in the interface board and turns on the power.
- 12. Electrical Characteristics ❖ The PCI bus is defined for operation with either a 5V or 3.3V power supply. ❖ Motherboard is designed to operate with signaling system. ❖ Connectors in the expansion board are designed to ensure that they can be plugged only in a compatible motherboard.