要写出Scan pci bus的程式首先必须先参考PCI的spec里面的Configuration SpaceHeader的图，而Class code有24个bit(3byte)，组要由三个部份组成，Base Class、Sub Class、 programming Interface 将的PCI BUS上的Base Class、Sub Class、programming Interface用原本的范例程式加上回圈去侦测。基本上只要了解pci的架构，再用范例程式就可以找出有在使用的pci device。-to write Scan pci bus programs must first consider the PCI spec inside Configuration SpaceHeader plans, and Class code is 24 bit (3byte), the group should be composed of three parts, the Base Class, Sub Class, programming Interface to the PCI BUS on the Base Class, Sub Class , Interface programming model with the original formula added to a circle to detect. Basically, as long as pci understand the structure and reuse examples of programs can be used to identify the pci device.