82503 Datasheet, PDF (9/45 Pages) Intel Corporation – DUAL SERIAL TRANSCEIVER (DST)

82503
2 7 LED Pins
Symbol
PLCC
Pin
TxLED
42
RxLED
43
COLED
44
LILED
41
POLED
1
QFP
Pin
36
37
38
35
39
Type
IO
IO
IO
O
O
Name and Function
TRANSMIT LED LED output Indicates transmit status of the AUI or
TPE port Normally off (high) output Turns on to indicate
transmission Flashes at a rate dependent on the level of transmit
activity Upon entering a customer test mode this pin must be
driven high either through an LED or a resistor
RECEIVE LED LED output Indicates receive status of the AUI or
TPE port Normally off (high) output Turns on to indicate reception
Flashes at a rate dependent on the level of receive activity Upon
entering a customer test mode this pin must be driven high either
through an LED or a resistor
COLLISION LED LED output Indicates collision status of the AUI
or TPE port Normally off (high) output Turns on to indicate
collision Flashes at a rate dependent on the level of collision
activity This pin is also used to determine which customer test
modes are entered
LINK INTEGRITY LED LED output Normally on (low) output which
indicates good link integrity on the TPE port during TPE mode
Remains on when link integrity function has been disabled Turns off
during AUI mode or when link integrity fails in TPE mode Minimum
off time is 100 ms minimum on time is set by the link integrity
function
POLARITY INDICATION LED output If the 82503 detects that the
receive TPE wires are reversed POLED will turn on (low) to indicate
the fault POLED remains on even if APOL XSQ is high and the
82503 has automatically corrected for the reversed wires
NOTE
1 The LED outputs have a weak pull-up capable of sourcing 500 mA They can sink 10 mA while still meeting TTL levels All
LEDs can be used as indication pins if no LED is needed Some of these outputs include pulse width conditioning which
should be accounted for in software
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