FINAL
Am79C100
Twisted-Pair Ethernet Transceiver Plus (TPEX Plus)
DISTINCTIVE CHARACTERISTICS
s
CMOS device provides IEEE 802.3-compliant
operation and low operating current from a
single +5 V supply
s
Power Down mode for reduced power
consumption in battery-powered applications
s
Automatic twisted-pair link integrity
s
Pin-selectable twisted-pair receive polarity
detection and automatic inversion of the receive
signal. Polarity indication output pin can
directly drive an LED.
s
Pin-selectable twisted-pair link integrity test
capability conforming to the IEEE 802.3
standard. Link status pin can directly drive
an LED.
s
Transmit, receive, and collision status
indications available on separate, dedicated
pins
s
Outputs can directly drive LEDs with pulses
stretched to ensure LED visibility
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Internal twisted-pair transmitter digital
predistortion circuit to reduce medium-induced
jitter
s
Pin-selectable SQE Test (heartbeat) enable
s
AUI loopback, Jabber Control, and SQE Test
functions comply with the 10BASE-T standard
s
User-selectable loopback operations
s
Pin-selectable twisted-pair receive threshold
programming for extended distance line lengths
GENERAL DESCRIPTION
The Am79C100 Twisted-Pair Ethernet Transceiver Plus
(TPEX Plus) is an integrated circuit that implements the
medium attachment unit (MAU) functions for the
twisted-pair medium, as specified by the supplement to
the IEEE 802.3 standard (Type 10BASE-T). This de-
vice provides the necessary electrical and functional
interface between the IEEE 802.3 standard attachment
unit interface (AUI) and the twisted-pair cable.
A network based on the 10BASE-T standard can use
unshielded twisted-pair cables, providing an economi-
cal solution to networking by allowing the use of existing
telephone wiring. The Am79C100 provides a minimal
component count and a cost-effective solution to the
design and implementation of 10BASE-T standard
networks.
TPEX Plus provides twisted-pair driver and receiver cir-
cuits, including on-board transmit digital predistortion,
receiver squelch, and an AUI port with pin-selectable
SQE Test enable. The device provides a number of ad-
ditional features, including Link Status indication with
automatic twisted-pair receive polarity detection/
correction and indication; pin-selectable receive
threshold programming for extended distance line
lengths; and Receive Carrier Sense, Transmit Active
and Collision Present indications. The device provides
separate twisted-pair Link Status, Polarity Status,
Receive, Transmit, and Collision outputs to drive LEDs
directly.
Publication#
16511
Rev:
B
Amendment/0
Issue Date:
May 1994
1
AMD [ ADVANCED MICRO DEVICES ]
