XR72L52 Datasheet, PDF (37/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
PIN DESCRIPTION
PIN #
159
160
PIN NAME
RxRed[0]
RxAIS[0]
TYPE
DESCRIPTION
O Receiver Red Alarm Indicator - Receive Framer:
The Framer asserts this output pin to denote that one of the following events has
been detected by the Receive Framer:
LOS - Loss of Signal Condition
OOF - Out of Frame Condition
AIS - Alarm Indication Signal Detection
O Receive Alarm Indication Signal Output pin:
The Framer assert sthis pin to indicate that the Alarm Indication Signal (AIS) has
been identified in the Receive DS3 or E3 data stream.
For DS3 Applications:
The Framer asserts this pin to indicate that the Alarm Indication Signal (AIS) has
been identified in the Receive DS3 data stream. An AIS is detected if the pay-
load consists of the recurring pattern of “1010...” and this pattern persists for 63
M-frames. An additional requirement for AIS indication is that the C-bits are set
to “0” and the X-bits are set to “1”. This pin is negated when a sufficient number
of frames not exhibiting the 1010... pattern in the payload has been detected.
For E3 Applications:
The Receive Section declares an AIS condition if it detects two consecutive E3
frames, each containing 7 or less 0’s.
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