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S/UNI-JET Data Sheet
Released
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
137
Register 334H: DS3 TRAN Configuration
Bit
Type
Function
Default
Bit 7
R/W
CBTRAN
0
Bit 6
R/W
AIS
0
Bit 5
R/W
IDL
0
Bit 4
R/W
FERF
0
Bit 3
R/W
Reserved
0
Bit 2
Unused
X
Bit 1
Unused
X
Bit 0
R/W
CBIT
0
CBIT
The CBIT bit enables the DS3 C-bit parity application. When CBIT is written with a logic
one, C-bit parity is enabled, and the S/UNI-JET modifies the C-bits as required to include the
path maintenance data link, the FEAC channel, the FEBE indication, and the path parity.
When CBIT is written with a logic zero, the M23 application is selected, and each C-bit is set
to logic one by the S/UNI-JET except for the first C-bit of the frame, which is forced to
toggle every frame. Note: The C-bits may be modified as required using the DS3 overhead
access port (TOH) regardless of the setting of this bit.
FERF
The FERF bit enables insertion of the far end receive failure maintenance signal in the DS3
stream. When FERF is written with a logic one, the X1 and X2 overhead bit positions are set
to logic zero. When FERF is written with a logic zero, the X1 and X2 overhead bit positions
in the DS3 stream are set to logic one.
IDL
The IDL bit enables insertion of the idle maintenance signal in the DS3 stream. When IDL is
written with a logic one, the DS3 payload is overwritten with the repeating pattern 1100.. The
DS3 overhead bit insertion (X, P, M F, and C) continues normally. When IDL is written with
a logic zero, the idle signal is not inserted.
AIS
The AIS bit enables insertion of the AIS maintenance signal in the DS3 stream. When AIS is
written with a logic one, the DS3 payload is overwritten with the repeating pattern 1010.. The
DS3 overhead bit insertion (X, P, M and F) continues normally. The values inserted in the C-
bits during AIS transmission are controlled by the CBTRAN bit in this register. When AIS is
written with a logic zero, the AIS signal is not inserted.