PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Enable
Disable
Enable
Disable
Enable
E1-EC
ED
Enable
Disable
Enable
E1-FB
FC
01101
01110
11100
E1-ED
EE
E1-FC
E1-EE
The RHPP monitors bits 5, 6 and 7 of the path status byte (G1) to detect path remote defect
indication (RDI-P) and path enhanced remote defect indication (ERDI-P) defects.
RDI-P is declared when bit 5 of the G1 byte is set high for five or ten consecutive frames
(selectable by the PRDI10 bit in the configuration register). RDI-P is removed when bit 5 of the
G1 byte is set low for five or ten consecutive frames. ERDI-P is declared when the same 010,
100, 101, 110 or 111 pattern is detected in bits 5, 6 and 7 of the G1 byte for five or ten
consecutive frames (selectable by the PRDI10 bit in the configuration register). ERDI-P is
removed when the same 000, 001 or 011 pattern is detected in bits 5, 6 and 7 of the G1 byte for
five or ten consecutive frames.
The RHPP extracts and serially outputs all the path overhead (POH) bytes on the time
multiplexed RPOH port. The POH bytes are output in the same order that they are received (J1,
B3, C2, G1, F2, H4, Z3, Z4 and N1). RPOHCLK is the generated output clock used to provide
timing for the RPOH port. RPOHCLK is a nominal 20.736 MHz clock generated by gapping a
25.92 MHz clock. Sampling RPOHFP high with the rising edge of RPOHCLK identifies the MSB
of the first J1 byte.
10.6 SONET/SDH Virtual Container Aligner (SVCA)
The SONET (SDH) Virtual Container Aligner (SVCA) block aligns the payload data from an
incoming SONET (SDH) data stream to a new transport frame reference. The alignment is
accomplished by recalculating the STS (AU) payload pointer value based on the offset between
the transport overhead of the incoming data stream and that of the outgoing data stream.
Frequency offsets (e.g., due to plesiochronous network boundaries, or the loss of a primary
reference timing source) and phase differences (due to normal network operation) between the
incoming data stream and the outgoing data stream are accommodated by pointer adjustments in
the outgoing data stream.
10.6.1 Elastic Store
The Elastic Store performs rate adaptation between the line side interface and the system side
interface. The entire incoming payload, including path overhead bytes, is written into a first-in-
first-out (FIFO) buffer at the incoming byte rate. Each FIFO word stores a payload data byte and
a one bit tag labeling the J1 byte. Incoming pointer justifications are accommodated by writing
into the FIFO during the negative stuff opportunity byte or by not writing during the positive stuff
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
62
PMC [ PMC-SIERRA, INC ]
