PM5342 Datasheet, PDF (495/558 Pages) PMC-Sierra, Inc – SONET/SDH Payload Extractor/Aligner

DATA SHEET
PMC-970133
ISSUE 4
PM5342 SPECTRA-155
SONET/SDH PAYLOAD EXTRACTOR/ALIGNER
Figure 61 - STS-3c (STM-1/AU4) Nibble Mode GENERATED Bus Timing
ACK
GFP
GMFP
GD[1:0]
GPL
TOH C1 TOH C1 TOH C1 SPE 1
00B
00B
00B
00B
SPE 2
00B
SPE 3
00B
GC1J1V1
GDP
TOH H2 POH J1 SPE 785 SPE 786 V1/NPI V1/NPI
00B
00B
00B
00B
01B
01B
The figure above shows the STS-3c (STM-1/AU4) nibble mode GENERATED
bus timing of an equivalent STS-3c (STM-1/AU4) sequence as in the byte mode
illustration. ACK is a 38.88 MHz clock. The frame pulse GFP marks the upper
nibble of the first synchronous payload envelope byte in the STS-3c
(STM-1/AU4) frame. The tributary multiframe frame pulse GMFP marks the
upper nibble of the third byte after the J1 byte, in the first frame of a multiframe
sequence, in an STS-3c (STM-1/AU4) stream. The respective positions marked
by GFP and GMFP are maintained by an internal fly-wheel counters thus they
need not be asserted on every frame. The GD[1:0] signals sequence through
01B, 10B, 11B and 00B and changing values on the third byte following the J1
byte in the STS-3c (STM-1/AU4) stream. This is to indicate (control) the current
tributary multiframe sequence in the STS-3c (STM-1/AU4) stream with 01B
indicating the first frame. The GPL signal marks both nibbles of each payload
byte in the STS-3c (STM-1/AU4) stream. The composite signal GC1J1V1 which
marks the C1, J1 and optionally, the V1 byte positions in the STS-3c
(STM-1/AU4) stream is asserted when the upper nibbles of these bytes are
transferred. Only the first C1 byte in an STS-3c (STM-1/AU4) frame will be
indicated. For STS-3c (STM-1/AU4), only the first V1 (if required) byte in the first
STS-3c (STM-1/AU4) frame of a tributary multiframe will be indicated. For
STS-3c (STM-1/AU4), the V1 pulse marks the more significant byte of the Null
Pointer Indication (NPI). The GENERATED bus parity output GDP reports the
parity of GD[1:0] and optionally includes GPL and GC1J1V1.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE 473