XRT73R12_07 Datasheet, PDF (29/89 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

REV. 1.0.2
XRT73R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
SYMBOL
PARAMETER
RxClk Duty Cycle
RxClk Frequency
E3
DS-3
STS-1
t_RRX RxClk rise time (10% o 90%)
t_FRX RxClk falling time (10% to 90%)
t_CO RxClk to RPOS/RNEG delay time
t_LCVO RxClk to rising edge of LCV output delay
MIN
TYP
MAX
UNITS
45
50
55
%
34.368
44.736
51.84
2
4
2
4
4
2.5
MHz
MHz
MHz
ns
ns
ns
ns
3.6 B3ZS/HDB3 Decoder
The decoder block takes the output from the clock and data recovery block and decodes the B3ZS (for DS3 or
STS-1) or HDB3 (for E3) encoded line signal and detects any coding errors or excessive zeros in the data
stream. Whenever the input signal violates the B3ZS or HDB3 coding sequence for bipolar violation or
contains three (for B3ZS) or four (for HDB3) or more consecutive zeros, an active “High” pulse is generated on
the RLCV_n output pins to indicate line code violation.
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