S/UNI®-JET Data Sheet
Released
Register 300H: S/UNI-JET Configuration 1
Bit
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Function
8KREFO
DS27_53
TOCTA
FRMRONLY
LOOPT
LLOOP
DLOOP
PLOOP
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
1
0
0
0
0
0
0
PLOOP
The PLOOP bit controls the DS3, E3, or J2 payload loopback. When a logic zero is written to
PLOOP, DS3, E3, or J2 payload loopback is disabled. When a logic one is written to PLOOP,
the DS3, E3, or J2 overhead bits are regenerated and inserted into the received DS3, E3, or J2
stream and the resulting stream is transmitted. Setting the PLOOP bit disables the effect of
the TICLK bit in the S/UNI-JET Transmit Configuration Register, thereby forcing flow-
through timing. The TFRM[1:0] and RFRM[1:0] bits in the S/UNI-JET Transmit
Configuration and Receive Configuration Registers, respectively, must be set to the same
value for PLOOP to work properly.
DLOOP
The DLOOP bit controls the diagnostic loopback. When a logic zero is written to DLOOP,
diagnostic loopback is disabled. When a logic one is written to DLOOP, the transmit data
stream is looped in the receive direction. The TFRM[1:0] and RFRM[1:0] bits in the S/UNI-
JET Transmit Configuration and Receive Configuration Registers, respectively, must be set to
the same value for DLOOP to work properly. The DLOOP should not be set to a logic one
when either the PLOOP, LLOOP, or LOOPT bit is a logic one. When in DS3, E3, or J2
modes, the TUNI register bit in the S/UNI-JET Transmit Configuration Register should be set
to the same value as the UNI bit in the DS3, E3, or J2 FRMR Registers.
LLOOP
The LLOOP bit controls the line loopback. When a logic zero is written to LLOOP, line
loopback is disabled. When a logic one is written to LLOOP, the stream received on
RPOS/RDATI and RNEG/RLCV/ROHM is looped to the TPOS/TDATO and TNEG/TOHM
outputs. Note: The TPOS, TNEG, and TCLK outputs are referenced to RCLK when LLOOP
is logic one.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
82
PMC [ PMC-SIERRA, INC ]
