S/UNI®-8x155 ASSP Telecom Standard Product Data Sheet
Released
DLE:
The Diagnostic Loopback, DLE bit enables the channel’s diagnostic loopback where the
channel’s Transmit ATM and POS Processors (TXCP and TXFP respectively) are directly
connected to the Receive ATM and POS Processor (RXCP and RXFP respectively). When
DLE is logic one, loopback is enabled. Under this operating condition, the channel does not
operate normally in the transmit direction or receive direction. When DLE is logic zero, the
channel operates normally.
The receive APS enable RXEN must be low while DLE is high in order for the loopback to
operate correctly.
TFPEN:
The Transmit Frame Pulse Enable (TFPEN) enables the TFPI input. When TFPEN is set
low, the channel ignores the TFPI input. When TFPEN is set high, the TFPI input is used
by the channel for frame alignment.
Since the TFPI input is sampled by the rising edge of TCLK, the TFPI input is affected by
clock source TSEL[1:0] configuration. A channel may use TFPI input only if the channel’s
TCLK is frequency locked to the TCLK of the channel selected by TSEL[4:0]. In general,
channel’s operating in loop timed must set TFPEN low.
SDH_J0/Z0
The SDH_J0/Z0 bit selects whether to insert SONET or SDH format J0/Z0 section
overhead bytes into the transmit stream. When SDH_J0/Z0 is set high, SDH format J0/Z0
bytes are selected for insertion. For this case, all the J0/Z0 bytes are forced to the value
programmed in the channel’s Transmit J0/Z0 register. When SDH_J0/Z0 is set low, SONET
format J0/Z0 bytes are selected for insertion. For this case, the J0/Z0 bytes of an STS-N
signal are numbered incrementally from 1 to N.
TSTBEN can be used to overwrite the first J0/Z0 byte of an STS-N signal.
TSTBEN:
The TSTBEN bit controls whether the section trace message stored in the SSTB block is
inserted into the transmit stream (i.e., the first J0/Z0 byte). When TSTBEN is set high, the
message stored in the SSTB is inserted into the transmit stream. When TSTBEN is set low,
the section trace message is supplied by the TSOP block.
TPTBEN:
The TPTBEN bit controls whether the path trace message stored in the SPTB block is
inserted into the transmit stream (i.e., the J1 byte). When TPTBEN is set high, the message
stored in the SPTB is inserted into the transmit stream. When TPTBEN is set low, the path
trace message is supplied by the TPOP block.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC- 2010299, Issue 2
119
PMC [ PMC-SIERRA, INC ]
