PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 116

• Manufacturer Part Number: PM5366-PI
• Description: HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER AND M13 MULTIPLEXER
• Manufacturer: PMC-Sierra, Inc.

PRELIMINARY
DATASHEET
PMC-2010672
9.27.2 DS3 Demapper Elastic Store
PROPRIETARY AND CONFIDENTIAL
• valid M-frame alignment bits (M-bits), M-subframe alignment bits (F-bits), and
• all the C-bits in the M-frame are set to zeros
• the X-bits are set to ones
• the information bit (84 Data bits with repeating sequence of 1010..)
Given a path signal label mismatch (PSLM) or path signal label unstable (PSLU),
the D3MD ignores the STS-1 (STM-0/AU3) SPE and writes a DS3 AIS pattern to
the elastic store. In addition, the desynchronization algorithm assumes a nominal
ratio of data to stuff bits carried in the S bits (1 out of 3 S bits is assumed to be
an information (data) bit). DS3 AIS is shown in Table 6.
Table 6
parity bit of the preceding M-frame (P-bits). The two P-bits are identical, either
both are zeros or ones.
The elastic store block is provided to compensate for frequency differences
between the DS-3 stream extracted from the STS-1 (STM-0/AU3) SPE and the
CLK52M clock input. The DS3 Demapper extracts I bits from the STS-1
(STM-0/AU3) SPE and writes the bits into a 128 bit (16 byte) elastic store. Eight
bytes are provided for SONET/SDH overhead (3 bytes for TOH, 1 byte for a
positive stuff, 1 byte for POH) and DS3 reserve stuffing bits (2 bytes for R bits,
and 3 overhead bits which is rounded-up to 1 byte). The remaining 8 bytes are
provided for path pointer adjustments.
Data is read out of the Elastic Store using a divide by 8 version of the input
CLK52M clock. If an overflow or underflow condition occurs, an interrupt is
X (1)
X (1)
P (p)
P (p)
M (0)
M
(1)
M
(0)
D
D
D
D
D
D
D
F (1)
F (1)
F (1)
F (1)
F (1)
F (1)
F (1)
- DS3 AIS format.
D
D
D
D
D
D
D
ISSUE 1
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
D
D
D
D
D
D
D
F (0)
F (0)
F (0)
F (0)
F (0)
F (0)
F (0)
D
D
D
D
D
D
D
104
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
D
D
D
D
D
D
D
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
F (0)
F (0)
F (0)
F (0)
F (0)
F (0)
F (0)
D
D
D
D
D
D
D
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
C (0)
AND M13 MULTIPLEXER
PM5366 TEMAP-84
D
D
D
D
D
D
D
F (1)
F (1)
F (1)
F (1)
F (1)
F (1)
F (1)
D
D
D
D
D
D
D