VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC870

High Performance Serial

Backplane Transceiver

Page 2

G52190-0, Rev 4.1

01/05/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

General Description

The VSC870 serial backplane transceiver has been designed to operate with the VSC880 serial crosspoint switch

to establish a synchronous high performance switching system. The VSC870 can also connect directly to another

transceiver to act as a high bandwidth backplane interconnect link. The transmitter converts a 32-bit parallel interface

operating at 62.5Mb/s to a 34-bit serial data stream operating a 2.125Gb/s. The receiver converts a 34-bit serial

interface operating at 2.125Gb/s to a 32-bit parallel interface operating at 62.5Mb/s. The transceiver performs

automatic bit alignment, word alignment and cell alignment to a connected switch chip or another transceiver. The

parallel interface has been designed with industry-standard FIFOs in mind to provide such features as automatic

packet retransmission, multicast with retransmission, camp-on and support for virtual output queues. These features

can also be bypassed to give the user direct control of the serial data stream. In addition, the transceiver and switch

chip can operate in a early arbitration mode that greatly improves bandwidth utilization. The transceiver also contains

a built-in a flow control channel and redundant serial I/O buffers.

The transceiver and switch chip have been optimized to be used in both distributed-controlled packet-based

switching systems (Packet Mode), and centrally-controlled cell-based switching systems (Cell Mode). The

transceiver can also be directly connected to another transceiver (Direct Mode) for backplane interconnect

applications. The transceiver runs off a 3.3V power supply. The serial I/O buffers contain on-chip termination

resistors (See Figure 19).