S/UNI®-JET Data Sheet
Released
10 Functional Description
The S/UNI-JET contains the following blocks:
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DS3, E3, J2 Framer
DS3, E3, J2 Transmitter
RBOC Bit oriented code detector and XBOC Bit oriented code detector
RDLC PMDL receiver and TDPR PMDL transmitter
PMON Performance monitor and CPPM Cell and PLCP performance monitor
SPLR PLCP layer receiver and SPLT SMDS PLCP Layer Transmitter
ATMF ATM cell delineator
PRGD Pseudo-random sequence generator/detector
RXCP Receive cell processor and TXCP Transmit cell processor
RXFF Receive FIFO and TXFF Transmit FIFO
TTB Trail trace buffer
JTAG Test access port
10.1 DS3 Framer
The DS3 Framer (T3-FRMR) Block integrates the circuitry required for decoding a
B3ZS-encoded signal and framing to the resulting DS3 bit stream. This block is directly
compatible with the M23 and C-bit parity DS3 applications.
The T3-FRMR decodes a B3ZS-encoded signal and provides indications of LCV (LCV). The
B3ZS decoding algorithm and the LCV definition can be independently chosen through software.
A LOS defect is also detected for B3ZS encoded streams. LOS is declared when inputs RPOS and
RNEG contain zeros for 175 consecutive RCLK cycles. LOS is removed when the ones density
on RPOS and/or RNEG is greater than 33% for 175 ±1 RCLK cycles.
The framing algorithm simultaneously examines five F-bit candidates. When at least one
discrepancy has occurred in each candidate, the algorithm examines the next set of five. When a
single F-bit candidate remains in a set, the first bit in the supposed M-subframe is examined for
the M-frame alignment signal such as, the M-bits, M1, M2, and M3 are following the 010 pattern.
If the M-bits are correct for three consecutive M-frames while no discrepancies have occurred in
the F-bit, framing is declared and out-of-frame (OOF) is removed. During the examination of the
M-bits, the X-bits and P-bits are ignored. The algorithm gives a maximum average reframe time
of 1.5 ms.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
54
PMC [ PMC-SIERRA, INC ]
