PRELIMINARY
PM4318 OCTLIU
DATASHEET
PMC- 2001578
ISSUE 3
OCTAL E1/T1/J1 LINE INTERFACE DEVICE
of a tributary on the SBI interface causes the bipolar TXTIP[n] and TXRING[n] outputs to be
forced to pulse alternately, creating an all-ones signal. The transition to transmitting AIS on
the TXTIP[n] and TXRING[n] outputs is done in such a way as to avoid introducing any
bipolar violations.
The diagnostic digital loopback point is prior to the AIS insertion point.
TDUAL:
The TDUAL bit configures the LIU transmit path for dual-rail (bipolar) operation. When
TDUAL is set to logic 1, NRZ bipolar positive and negative data is input on TDP[n] and
TDN[n] respectively. When TDUAL is set to logic 0, NRZ unipolar data is input on TDP[n] and
TDN[n] is ignored. TDUAL must be set to logic 0 when operating in SBI mode (i.e. when the
SBI_EN input is logic 1).
If TDUAL is set to logic 1, the XIBC, XPDE, LCODE and PRBS blocks are disabled in the LIU
transmit path.
AMI:
The AMI bit enables AMI line coding. If AMI is set to a logic 1, the LIU will perform AMI line
encoding on the TDP[n] single-rail input data stream. If AMI is set to a logic 0, the LIU will
perform B8ZS (if operating in T1 mode) or HDB3 (if operating in E1 mode) line encoding on
the TDP[n] data stream. The AMI bit is ignored if the TDUAL bit is set to logic 1.
TINV:
When TINV is set to logic 1, the transmit digital inputs TDP[n] and TDN[n] are assumed to be
active low and all input data is inverted. When TINV is set to logic 0, the transmit digital
inputs TDP[n] and TDN[n] are assumed to be active high.
TRISE:
When TRISE is set to logic 1, the TDP[n] and TDN[n] inputs are sampled on rising edges of
TCLK[n]. When TRISE is set to logic 0, the inputs are sampled on falling edges of TCLK[n].
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
72
PMC [ PMC-SIERRA, INC ]
