STANDARD PRODUCT
PM4328 TECT3
DATASHEET
PMC-2011596
ISSUE 1
HIGH DENSITY T1/E1 FRAMER
AND M13 MULTIPLEXER
multiframe alignment signals are observed within 8 ms, with the time separating
two alignment signals being a multiple of 2 ms
Once CRC multiframe alignment is found, the OOCMFV register bit is set to
logic 0, and the E1-FRMR monitors the multiframe alignment signal, indicating
errors occurring in the 6-bit MFAS pattern, errors occurring in the received CRC
and the value of the FEBE bits (bit 1 of frames 13 and 15 of the multiframe).
The E1-FRMR declares loss of CRC multiframe alignment if basic frame
alignment is lost. However, once CRC multiframe alignment is found, it cannot
be lost due to errors in the 6-bit MFAS pattern.
Under the CRC-to-non-CRC interworking algorithm, if the E1-FRMR can achieve
basic frame alignment with respect to the incoming PCM data stream, but is
unable to achieve CRC-4 multiframe alignment within the subsequent 400 ms,
the distant end is assumed to be a non CRC-4 interface. The details of this
algorithm are illustrated in the state diagram in Figure 7.
PROPRIETARY AND CONFIDENTIAL
58
PMC [ PMC-SIERRA, INC ]
