PM7347 datasheet(54/341 Pages) PMC

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S/UNI®-JET Data Sheet

Released

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

Document ID: PMC-1990267, Issue 3

Functional Description

The S/UNI-JET contains the following blocks:

• 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.

PM7347 Datasheet(PDF) 54 Page - PMC-Sierra, Inc