April 1997
ML4642 AUI Multiplexer
GENERAL DESCRIPTION
The ML4642 AUI Multiplexer contains all the necessary
drivers/receivers and control logic to implement a 2 port
MAU when used in conjuction with a transceiver chip
which has a standard 802.3 AUI interface. In addition, the
ML4642 is capable of operating in stand-alone mode
where it interconnects two DTEs in the absence of a
network MAU. Several ML4642s can be cascaded
together to implement a 4 or 8 port MAU or stand-alone
device.
Logic within the ML4642 detects collisions resulting from
multiple DTEs transmitting simultaneously. In addition,
collision signals received from a transceiver attached at
the MAU port are propagated to both of the DTE ports.
Jabbering DTEs are prevented from loading down the
network by internal jabber timers which disable babbling
ports.
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FEATURES
IEEE 802.3 compliant AUI interfaces assure
compatibility with any AUI ready devices
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No crystal or clock input
On-chip Jabber logic, Collision Detection, and SQE
test with enable/disable option
Selectable Loopback, Jabber, and SQE Test allows
cascading of multiple chips to increase DTE port
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BLOCK DIAGRAM
+5V
61.9K
RRSET
V
CC
V
CC
CONTROL
LOGIC
TXIN1P
TXIN1N
RXOUT1P
RXOUT1N
CDOUT1P
CDOUT1N
TXIN2P
TXIN2N
RXOUT2P
RXOUT2N
CDOUT2P
CDOUT2N
LED DRIVERS
MAU
AUI
INTERFACE
CI MUX
MAU
AUI
INTERFACE
JABBER
DO MUX
DTE
AUI
INTERFACE
TXOUTP
TXOUTN
DI MUX
RXINP
RXINN
CDINP
CDINN
SQE SOURCE
GND
JAB1/JDIS
JAB2
CDLED
RXLED/LPBK/SQE
TXLED1
TXLED2
1