Full Duplex
80C25
80C25
AutoDUPLEXTM
CMOS Ethernet Interface Adapter
in 28L Package
96345
Functional Features
Note: Check for latest Data Sheet revision
before starting any designs.
s Low Power CMOS Technology Ethernet Serial
Interface Adapter with Integrated Manchester
Code Converter (MCCTM), AUI and 10Base-T
Transceiver with Output Wave Shaping and on
chip filters.
SEEQ Data Sheets are now on the Web, at
www.lsilogic.com.
This document is an LSI Logic document. Any
reference to SEEQ Technology should be
considered LSI Logic.
s Meets IEEE 802.3 10Base-5, 10Base-2, 10Base-T
Standards
s Direct Interface to SEEQ & INTEL Controllers,
See the 80C26 Data Sheet for Direct Interface to
AMD and NSC Controllers
Interface Features
s Meets IEEE 10Base-T Standards and IEEE 802.3
standards for AUI.
s Automatic or Manual Selection of AUI/10Base-T
Interface
s On Chip Transmit Wave Shaping and Low Pass
Filter Circuits - No External Filters Required
s Provides AutoDUPLEXTM Detect Function for
SEEQ LAN Controllers, Doubling Bandwidth
to 20 MBits/sec for Switched Networks
s Link Integrity Test Disable, Selectable Coded
Link Pulse for AutoDUPLEX Mode
s Low differential and common mode noise on TP
transmit outputs.
s Direct AUI interface to the Manchester Code
Converter.
26 REXT
FDPLX
28 GND 1
27
1
3
2
4
VCC1
s Differential Transmit Drivers to support 50 Meters
of AUI Cable Lengths.
CIS
Pin Configuration
TP/AUI
s Automatic Polarity Correction
DO +
s Separate Analog/Digital Power and Ground Pins
to Minimize Noise
General Description
DO –
5
25
TPO +
CI +
6
24
TPO –
CI –
7
23
The SEEQ 80C25 is a CMOS single chip Ethernet serial
interface adapter with a integrated Manchester Code
Converter (MCC), AUI & 10Base-T transceiver with wave
shaping & filters eliminating the need for external filters.
The 80C25 is designed to interface directly with SEEQ and
Intel Ethernet data link controllers. The chip provides
automatic polarity correction, automatic port selection,
separate analog & digital ground pins & a link disable
feature. It also provides a selectable coded link pulse to
implement AutoDUPLEX function together with SEEQ
family of controllers allowing seamless full duplex operation in switched network implementations doubling network bandwidth to 20 Mbps in 10Base-T. The 80C25 is
typically suitable for adapter boards, motherboards and
stand-alone TP transceiver designs & switching hubs.
TPI +
28 Pin PLCC
Top View
TXD
FDPLX_DET 11
19
RXD
RXC
CSN
18
20
X1 17
LNK_LED/LNK_DIS 10
GND 2 16
TXEN
VCC2 15
TPI –
21
COL 14
22
9
TXC 13
8
DI –
12
DI +
MCC and AutoDUPLEX are trademarks of SEEQ Technology, Inc.
1
MD400142/D
