W89C840AF

W89C840AF is a highly integrated Ethernet LAN controller for both 100BaseT and 10BaseT Ethernet. It provides a host bus interface complying with the PCI local bus specification revision 2.1, and the MII interface complying with the IEEE802.3u standard for easily implementing an Ethernet LAN adapter. The built-in 2K bytes transmit FIFO and 4K bytes receive FIFO, controlled by the on-chip bus master, are designed for improving network performance and reducing the host bus utilitzation.

The on-chip DMA controller W89C840AF handles the data transfer between the host memory and the FIFOs. The data received from network are queued into the receive FIFO and then, directly moved into the host memory through the PCI bus. On the other hand, the transmitted data are fetched from the host memory and directly queued into the transmit FIFO. No extra on-board memory is needed for data buffering during the data transceiving operation.

For featuring the specifications of PC97/98, W89C840AF implements power management functinos which are compliant with Advanced Configuration and Power Interface ( ACPI) specification Rev. 1.0, PCI Power Management Interface specification Rev. 1.0, and Network Device Class Power Management Reference specification V1.0a as well as remote wakeup function based on the OnNow initiative and the ACPI specification requirement of PC 97 and PC 98.

Many versatile registers, total 48 inside, including host bus control registers, direct memory  access(DMA) control registers, media access control registers(MAC), power management control/status registers and signature identification registers, are implemented for system configuring and control. All of these long word accessible registers perform the status report and the precisely control on the operation of transmit and receive. W89C840AF also provides an extra channel for the on-line application program to update the on-board expansion ROM device in some specific application environment.