The PCI bus is a high performance local bus architecture with low latency random access time. It is a synchronous bus with operation up to 33MHz. The PCI bus interface is designed to provide the registers with the device information required for configuration, recording the status of the lines , control registers, interrupt line and I/O base address registers. It is capable of functioning in a half-duplex environment. The W89C940Fis designed to fully comply with the standard of PCI 2.0 specification. Taking advantage of PCI's nature, W89C940F supports auto-configuration function to free users' depression and confusion on tunning system resources conflict. With extremely high throughput on PCI bus, W89C940F offers a 32 bits data path to highly boost its performance without extra cost. Comparing with LAN card with ISA bus, its improvement is excellent. Besides, it also supports up to 256KB flash memory reserved for various applications, for instance anti-virus, popular drivers, Boot ROM, viewing your PC assets...etc., and what is more, these software are able to be updated on line. This can increase more niche feature on your LAN card, help you get more and bright your company profile. W89C940F is a single chip - build-in PCI bus interface and all necessary circuits - which will let design and board assembly become easy.