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STANDARD PRODUCT
PMC-Sierra, Inc.
PM6344 EQUAD
PMC-951013
ISSUE 5
QUADRUPLE E1 FRAMER
80
Register 00AH, 08AH, 10AH, 18AH: Master Diagnostics
Bit
Type
Function
Default
Bit 7
Unused
X
Bit 6
Unused
X
Bit 5
R/W
PAYLB
0
Bit 4
R/W
LINELB
0
Bit 3
Unused
X
Bit 2
R/W
DDLB
0
Bit 1
Unused
X
Bit 0
R/W
TXDIS
0
This register allows software to enable diagnostic modes.
PAYLB:
The PAYLB bit selects the payload loopback mode, where the received data
output from the ELST is internally connected to the transmit data input of the
TRAN. The data read out of ELST is timed to the transmitter clock, and the
transmit frame alignment is used to synchronize the output frame alignment
of ELST. During payload loopback, the data output on BRPCM[x] is forced to
logic 1. When PAYLB is set to logic 1, the payload loopback mode is enabled.
When PAYLB is set to logic 0, the loopback mode is disabled.
LINELB:
The LINELB bit selects the line loopback mode, where the recovered positive
and negative pulse outputs from the CDRC block are internally connected to
the digital inputs of the DJAT. When LINELB is set to logic 1, the line
loopback mode is enabled. When LINELB is set to logic 0, the line loopback
mode is disabled. Note that when line loopback is enabled, the Timing
Options Register settings should be reviewed to ensure the options are such
that data will pass error-free and "jitter"-free through DJAT (typically, the
default setting, 00H, for register 7 will be appropriate for line loopback).
DDLB:
The DDLB bit selects the diagnostic digital loopback mode, where the
transmit side outputs from DJAT are internally connected to the receive side
inputs. When DDLB is set to logic 1, the diagnostic digital loopback mode is