AM79761 Datasheet, PDF (1/20 Pages) Advanced Micro Devices – Physical Layer 10-Bit Transceiver for Gigabit Ethernet (GigaPHY™-SD)

PRELIMINARY
Am79761
Physical Layer 10-Bit Transceiver for Gigabit Ethernet
(GigaPHY™-SD)
DISTINCTIVE CHARACTERISTICS
n Gigabit Ethernet Transceiver operates at
1.25 Gigabits per second (Gbps)
n Suitable for both Coaxial and Optical Link
applications
n 10-bit TTL Interface for Transmit and Receive
Data
n Monolithic Clock Synthesis and Clock Recovery
requires no external components
n Word Synchronization Function (Comma
Detect)
n Low Power Operation - 700 mW typical
n 64-pin Standard PQFP
— 14 x 14 mm (0˚ C - 70˚ C)
— 10 x 10 mm (0˚ C - 50˚ C)
n 125 MHz TTL Reference Clock
n Loopback Diagnostic
n Single +3.3 V Supply
GENERAL DESCRIPTION
The Am79761 Gigabit Ethernet Physical Layer Serial-
izer/Deserializer (GigaPHY-SD) device is a 1.25 Gbps
Ethernet Transceiver optimized for Gigabit Ethernet/
1000BASE-X applications. It implements the Physical
Medium Attachment (PMA) layer for a single port.
The GigaPHY-SD device can interface to fiber-optic
media to support 1000BASE-LX and 1000BASE-SX
applications and can interface to copper coax to sup-
port 1000BASE-CX applications.
The functions performed by the device include serializ-
ing the 8B/10B 10-bit data for transmission, deserializ-
ing received code groups, recovering the clock from the
incoming data stream, and word synchronization.
When transmitting, the GigaPHY-SD device receives
10-bit 8B/10B code groups at 125 million code groups
per second. It then serializes the parallel data stream,
adding a reference clock, and transmits it through the
PECL drivers.
When receiving, the GigaPHY-SD device receives the
PECL data stream from the network. It then recovers
the clock from the data stream, deserializes the data
stream into a 10-bit code group, and transmits it to the
Physical Coding Sublayer (PCS) logic above. Option-
ally, it detects comma characters used to align the in-
coming word.
This document contains information on a product under development at Advanced Micro Devices. The information
is intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice.
Publication# 21560 Rev: A Amendment/+1
Issue Date: April 1998