12
C
HAPTER
1: I
NTRODUCTION
Hardware Features
Interoperability
Operates with existing Ethernet equipment
Compliance with
PCI Local
Bus Specification Version 2.0
and
2.1
Compatible with a 32- or 64-bit, 33/66 MHz
PCI bus master slot. As a bus master NIC, the NIC
requests access to the PCI bus instead of waiting to
be polled by the host. An innovative DMA algorithm
enables the 3C985B-SX server NIC to automatically
learn and conform to a particular host’s PCI bus
and memory system requirements, maximizing
performance and host efficiency.
Full-duplex Gigabit Ethernet
interface
IEEE 802.3z
Frame-based flow control
IEEE 802.3x
Gigabit Ethernet
fiber interface
62.5/125 µm or 50/125 µm multimode fiber, using a
duplex SC connector
Adaptive interrupt frequency The 3C985B-SX server NIC driver intelligently adjusts
host interrupt frequency based on traffic conditions
to increase overall application throughput. In light
traffic, the NIC driver interrupts the host for each
received packet, minimizing latency. When traffic is
heavy, the NIC issues one host interrupt for multiple,
back-to-back incoming packets, preserving host
CPU cycles.
Dual DMA channels
The PCI interface on the 3C985B-SX server NIC
contains two independent DMA channels for
simultaneous read and write operations.
ASIC with on-chip MAC
and RISC processor
The core control for the 3C985B-SX server NIC
resides in a tightly integrated, high-performance
ASIC. Embedded RISC processors in the ASIC provide
the flexibility to add new features to the NIC and
adapt it to future changes in network requirements
through software downloads. This embedded RISC
processor enables NIC drivers to exploit built-in
functions on the NIC that offload operations
from the host to the NIC.
Universal dual-voltage
signaling
3.3 V and 5 V
Status LEDs
LINK and DATA
Diagnostic support
Diagnostics programs run under DOS or Windows NT.
Book Page 12 Monday, June 7, 1999 2:14 PM
