PM4341AT1XC
DATA SHEET
PMC-900602
ISSUE 7
T1 FRAMER/TRANSCEIVER
in the PCM stream for at least 5.1 seconds.The code sequence detection and
timing is compatible with the specifications defined in T1.403-1989, TA-TSY-
000312, and TR-TSY-000303. LOOPBACK ACTIVATE and DEACTIVATE code
indication is provided through internal register bits. An interrupt is generated to
indicate when either code status has changed.
8.7 Pulse Density Violation Detector (PDVD)
The Pulse Density Violation Detection function is provided by the PDVD block.
The TSB detects pulse density violations of the requirement that there be N ones
in each and every time window of 8(N+1) data bits (where N can equal 1 through
23).The PDVD also detects periods of 16 consecutive zeros in the incoming
data. Pulse density violation detection is provided through an internal register bit.
An interrupt is generated to signal a 16 consecutive zero event, and/or a change
of state on the pulse density violation indication.
8.8 Performance Monitor Counters (PMON)
The Performance Monitor Counters function is provided by the PMON block.The
TSB accumulates CRC error events, Frame Synchronization bit error events, Line
Code Violation events, and Loss Of Frame events, or optionally, Change of
Frame Alignment (COFA) events with saturating counters over consecutive
intervals as defined by the period of the supplied transfer clock signal (typically 1
second). When the transfer clock signal is applied, the PMON transfers the
counter values into holding registers and resets the counters to begin
accumulating events for the interval.The counters are reset in such a manner
that error events occurring during the reset are not missed. If the holding
registers are not read between successive transfer clocks, an OVERRUN register
bit is asserted.
Generation of the transfer clock within the T1XC chip is performed by writing to
any counter register location. The holding register addresses are contiguous to
facilitate polling operations.
8.9 Bit Oriented Code Detector (RBOC)
The Bit Oriented Code detection function is provided by the RBOC block.This
block detects the presence of 63 of the possible 64 bit oriented codes
transmitted in the Facility Data Link channel in ESF framing format, as defined in
th
ANSI T1.403-1989 and in TR-TSY-000194.The 64 code (111111) is similar to
the DL FLAG sequence and is used by the RBOC to indicate no valid code
received.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
42
PMC [ PMC-SIERRA, INC ]
