STANDARD PRODUCT
PM5365 TEMAP
DATASHEET
PMC-1991148
ISSUE 3
HIGH DENSITY VT/TU MAPPER
AND M13 MULTIPLEXER
When configured for the C-bit parity application, all overhead bits are inserted.
When configured for the M23 application, all overhead bits except the stuff
control bits (the C-bits) are inserted; the C-bits are inserted by the upstream
MX23 TSB.
Status signals such as far end receive failure (FERF), the alarm indication signal,
and the idle signal can be inserted when their transmission is enabled by internal
register bits. FERF can also be automatically inserted on detection of any
combination of LOS, OOF or RED, or AIS by the DS3-FRMR.
A valid pair of P-bits is automatically calculated and inserted by the DS3-TRAN.
When C-bit parity mode is selected, the path parity bits, and far end block error
(FEBE) indications are automatically inserted.
When enabled for C-bit parity operation, the FEAC channel is sourced by the
XBOC bit-oriented code transmitter. The path maintenance data link messages
are sourced by the TDPR data link transmitter.
The DS3-TRAN supports diagnostic modes in which it inserts parity or path parity
errors, F-bit framing errors, M-bit framing errors, invalid X or P-bits, line code
violations, or all-zeros.
9.12 M23 Multiplexer (MX23)
The M23 Multiplexer (MX23) integrates circuitry required to asynchronously
multiplex and demultiplex seven DS2 streams into, and out of, an M23 or C-bit
Parity formatted DS3 serial stream.
When multiplexing seven DS2 streams into an M23 formatted DS3 stream, the
MX23 TSB performs rate adaptation to the DS3 by integral FIFO buffers,
controlled by timing circuitry. The C-bits are also generated and inserted by the
timing circuitry. Software control is provided to transmit DS2 AIS and DS2
payload loopback requests. The loopback request is coded by inverting one of
the three C-bits (the default option is compatible with ANSI T1.107a Section
8.2.1 and TR-TSY-000009 Section 3.7). The TSB also supports generation of a
C-bit Parity formatted DS3 stream by providing an internally generated DS2 rate
clock corresponding to a 100% stuffing ratio. Integrated M13 applications are
supported by providing an internally generated DS2 rate clock corresponding to a
39.1% stuffing ratio.
When demultiplexing seven DS2 streams from an M23 formatted DS3, the MX23
performs bit destuffing via interpretation of the C-bits. The MX23 also detects
and indicates DS2 payload loopback requests encoded in the C-bits. As per
ANSI T1.107a Section 8.2.1 and TR-TSY-000009 Section 3.7, the loopback
command is identified as C3 being the inverse of C1 and C2. Because TR-TSY-
Proprietary and Confidential to PMC-Sierra, Inc. and for its Customers’ Internal Use
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PMC [ PMC-SIERRA, INC ]
