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Editor to share with you what is the use of PCI Show in Component, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

PCI,Peripheral Component Interconnect is widely used in PC, and almost all motherboard products have this slot. It is mainly used to connect video card, network card, sound card and other peripherals. PCI bus is a tree structure, independent of CPU bus, and can operate in parallel with CPU bus. PCI devices and PCI bridges can be connected to the PCI bus, only one PCI master device is allowed on the PCI bus, and the rest are PCI slave devices, and the read and write operations can only be carried out between the master and slave devices. The data exchange between the slave devices needs to transfer to the VxWorks system through the master device to provide a set of commands to view the information of the PCI device. To use these commands, a component INCLUDE_PCI_CFGSHOW is provided in the traditional PCI driver.

However, at present, the VxBus driver is generally used in VxWorks 6.x, which is not compatible with INCLUDE_PCI_CFGSHOW, and VxBus also provides a component INCLUDE_PCI_BUS_SHOW, so there is no problem with this.

The following functions are mainly provided in this component

PciDeviceShow () is used to enumerate devices on a PCI bus

PciHeaderShow () is used to view the details of the device, such as the video memory base address and interrupt number of the video card.

If you know the ID of the device, you can use pciFindDeviceShow () to find it. For example, there are two AMD (0x1022) 79C97x network cards (0x2000) in the current Target.

PciConfigStatusWordShow () is used to view the status register

PciConfigCmdWordShow () is used to view the command register

If you only know the Class of the device, you can use pciFindClassShow () to find it

The common subclass are

Therefore, the classCode of the video card just now is (PCI_CLASS_DISPLAY_CTLR)

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