Specifications

HW400p/M Technical Reference - 1.0, March 6, 2002 I/O 13
3-3. I/O
DUART The Exar ST16C2550 Dual Universal Asynchronous Receiver/Transmitter
(DUART) provides connectivity to the two serial ports via a console accessory
kit.
10/100 Mbps Ethernet/Am79C973 The Am79C973 controller is a single-chip 32-bit full-duplex, 10/100-Mbps
fully integrated PCI-to-Wire Fast Ethernet controller.
The Am79C973 controller provides the following features:
• An Ethernet circuit that supports either 10BaseT or 100BaseTx
• Integrates the complete 10/100 PHY interface
• The internal 10/100 PHY implements Auto-Negotiation for twisted-pair
(10T/100X) operating as defined in the IEEE 802.3u specification
• 12k buffers
• 32-bit 33MHz PCI bus interface
• Four LEDS indicating the Ethernet status are surface-mounted on the
board along the top edge of the PCB near RJ-45 (see Section 4-4, LEDs)
• Accessible through RJ-45 (not front panel accessible)
Intel 21554 PCI-to-PCI Bridge The PCI bus interface is implemented using the Intel 21554 PCI/PCI
Translation Bridge chip operating at 33MHz on both the host PCI and local
PCI.
The PCI bus interface provides the following features:
• The 21554 is a PCI master or slave for memory and I/O accesses on a
33MHz/32- or 64-bit PCI bus
• 32-bit local bus
• A universal signaling device that operates at 3.3V but is also 5.0-V I/O-
tolerant
• A nontransparent PCI-to-PCI bridge that allows a local processor to
independently configure and control a local subsystem