AT79C1020 Datasheet, PDF (1/2 Pages) ATMEL Corporation – 4-port Layer 2 10/100/1000Mbps Unmanaged Switched Ethernet Controller

Features
• Supports Four 10/100/1000 Mbps Ethernet Ports with GMII/MII Interface
• IEEE 802.3ab CSMA/CD Compliant
• Full and Half Duplex Mode of Operation
• Speed and Duplex Mode Auto-negotiation Through MDIO
• Self-address Learning Mechanism Supports 512-MAC Addresses
• Automatic Address Aging with 300 seconds Default
• 512-kbit Packet Buffer Memory Embedded
• Serial Port Interface Employed to Communicate with MCU
• IEEE 802.3ab Flow Control for Full Duplex Operation
• Supports Store-and-Forward Mode of Operation
• 0.18 Micron, 1.8V CMOS Technology Packaged in 160-pin PQFP
• 3.3V I/O
• Available in a Variety of Packages Depending on Customer Requirements
Description
This Layer 2 Switch provides an ideal solution for the design of unmanaged full wire-
speed multi-port Gigabit Ethernet (GbE) switches. Each port supports either
10/100/1000 Mbps data rate. Flow controls, back pressure in half-duplex mode and
PAUSE frame in full-duplex mode are employed to solve the HOL (Head of Line)
blocking.
This Layer 2 Switch integrates four half/full duplex mode 1000 BASE Gigabit Ethernet
MACs, wire speed switching engines, MAC address based address parsing algorithms
and packet buffer memory.
4-port Layer 2
10/100/1000Mbps
Unmanaged
Switched Ethernet
Controller
AT79C1020
Summary
Figure 1. Ethernet Level 2 Switch Block Diagram
GMI
RXD
(RX_CLK)
FIFO
Request
Address _{Address Parse}
Port Num
Module
Ack
MII
TXD_nG
(TX_CLK)
Mux
GMII
TXD_G
(SYSCLK)
DataRate
MAC0, 1, 2 & 3
Switch
Fabric
Packet In
Packet Out
Packet Buffer
(48 kByte)
Control
Signals
Management
Interface
(SPI, MDIO)
SPI/MDIO
Switch Core
3434BS–NETST–3/04
Note: This is a summary document. A complete document
is available under NDA. For more information, please con-
tact your local Atmel sales office.