Search results
Results from the WOW.Com Content Network
Overview. PCI devices have a set of registers referred to as configuration space and PCI Express introduces extended configuration space for devices. Configuration space registers are mapped to memory locations. Device drivers and diagnostic software must have access to the configuration space, and operating systems typically use APIs to allow ...
Burst reads (using linear incrementing) are permitted in PCI configuration space. Unlike I/O space, standard PCI configuration registers are defined so that reads never disturb the state of the device. It is possible for a device to have configuration space registers beyond the standard 64 bytes which have read side effects, but this is rare. [30]
Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
The PCI-X standard was developed jointly by IBM, HP, and Compaq and submitted for approval in 1998. It was an effort to codify proprietary server extensions to the PCI local bus to address several shortcomings in PCI, and increase performance of high bandwidth devices, such as Gigabit Ethernet, Fibre Channel, and Ultra3 SCSI cards, and allow processors to be interconnected in clusters.
PCI Express devices communicate via a logical connection called an interconnect[ 10 ] or link. A link is a point-to-point communication channel between two PCI Express ports allowing both of them to send and receive ordinary PCI requests (configuration, I/O or memory read/write) and interrupts (INTx, MSI or MSI-X).
An option ROM for the PC platform (i.e. the IBM PC and derived successor computer systems) is a piece of firmware that resides in ROM on an expansion card (or stored along with the main system BIOS), which gets executed to initialize the device and (optionally) add support for the device to the BIOS. In its usual use, it is essentially a driver ...
A PCI-104 single-board computer. PC/104 (or PC104) is a family of embedded computer standards which define both form factors and computer buses by the PC/104 Consortium.Its name derives from the 104 pins on the interboard connector in the original PC/104 specification [1] [2] and has been retained in subsequent revisions, despite changes to connectors.
The Platform Controller Hub (PCH) is a family of Intel 's single-chip chipsets, first introduced in 2009. It is the successor to the Intel Hub Architecture, which used two chips–a northbridge and southbridge, and first appeared in the Intel 5 Series. The PCH controls certain data paths and support functions used in conjunction with Intel CPUs.