AM79C940JC/W AMD [Advanced Micro Devices], AM79C940JC/W Datasheet - Page 84

• Manufacturer Part Number: AM79C940JC/W
• Manufacturer: AMD [Advanced Micro Devices]

Attachment Unit Interface (AUI)
The AUI can drive up to 50 m of standard drop cable to
allow the transceiver to be remotely located, as is typi-
cally the case in IEEE 803.3 10BASE5 or thick Ether-
net® installations. For a locally mounted transceiver,
such as 802.3 10BASE2 or Cheapernet interface, the
isolation transformer requirements between the trans-
ceiver and the MACE device can be reduced.
84
10BASE5/Ethernet
10BASE2/Cheapernet
CPU
System
Engine
DMA
CPU
Local Bus
Memory
AUI-10BASE2/Cheapernet Example
Memory
Local
DTE
AUI-10BASE5/Ethernet Example
I/O Bus
Am79C940
Am79C940
When used with the Am79C98 TPEX
Ethernet Transceiver), the isolation requirements of the
AUI are completely removed providing that the trans-
ceiver is mounted locally. For remote location of the
TPEX via an AUI drop cable, the isolation requirement
is necessary to meet IEEE 802.3 specifications for fault
tolerance and recovery.
Cable
AUI
Transceiver
Am7996
Supply
Power
MAU
Transceiver
Am7996
Supply
Power
Cheapernet
Ethernet
16235D-15
Coax
Coax
BNC “T”
RG58
(Twisted Pair
16235D-14
Tap