This document contains information on a product under development at Advanced Micro Devices. The product is an integrated Fast Ethernet controller for the Peripheral Component Interconnect (PCI) bus. It features a high-performance bus mastering architecture with an integrated Direct Memory Access (DMA) Buffer Management Unit for low CPU and bus utilization. The product also supports various PCI features such as Plug and Play compatibility, advanced PCI commands, and PCI power management events. Additionally, it includes a Media Independent Interface (MII) for connecting external 10/100 Mbps transceivers.
The Am79C976 is a highly integrated 32‑bit Ethernet controller supporting 10 Mbps and 100 Mbps operation over a PCI bus. It offers full‑duplex, VLAN tagging, and extensive power‑management features suitable for PCs, network cards, and embedded designs.
This manual covers the controller’s distinctive characteristics, hardware block diagram, pin assignments, PCI and MII interfaces, power‑management options, and detailed programming registers. It also includes ordering information and reference tables for developers and system integrators.
| Supported Ethernet speeds | 10/100 Mbps |
|---|---|
| PCI interface width | 32‑bit |
| External SSRAM support | up to 4 Mbytes |
| Operating temperature range | -40 °C to +85 °C |
| PCI clock frequency support | 15 MHz to 33 MHz |
| VLAN support | Automatic VLAN tag insertion, deletion, modification |
It supports both 10 Mbps and 100 Mbps Ethernet speeds.
The controller can use up to 4 Mbytes of external SSRAM for frame storage.
Yes, it includes IEEE 802.1Q VLAN support with automatic tag insertion, deletion, and modification.
The industrial version operates from –40 °C to +85 °C.