PM6341 E1XC
DATA SHEET
PMC-910419
ISSUE 8
E1 FRAMER/TRANSCEIVER
locked-loop and recovers the NRZ data. Loss of signal is indicated after
exceeding a programmed threshold of 10, 31, 63 or 175 consecutive bit periods
of the absence of pulses on both the positive and negative line pulse inputs and
is cleared after the occurrence of a single line pulse. An alternate loss of signal
indication is provided which is cleared only after 255 bit periods during which no
sequence of four consecutive zeros has been received. If enabled, a
microprocessor interrupt is generated when a loss of signal is detected and when
the signal returns.
The HDB3 decoding is summarized as follows: If a bipolar violation (BPV)
preceded by two zeros is received, the violation and the preceding three bit
periods are decoded as four zeros. If AMI line code is selected, no substitution is
made.
If HDB3 line code is selected, a line code violation is declared if any bipolar
violation is of the same polarity as the previous BPV or if the BPV is not
preceded by two spaces (the second criteria is maskable). If AMI line code is
selected, all bipolar violations are counted as line code violations.
The input jitter tolerance of CDRC complies with ITU-T Recommendation G.823.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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PMC [ PMC-SIERRA, INC ]
