S/UNI®-JET Data Sheet
Released
M3O8
The M3O8 bit controls the DS3 OOF decision criteria. When a logic one is written to M3O8,
DS3 OOF is declared when three of eight framing bits (F-bits) are in error. When a logic zero
is written to M3O8, the three of 16 framing bits in error criteria is used, as recommended in
ANSI T1.107
MBDIS
The MBDIS bit disables the use of M-bit errors as a criteria for losing frame alignment.
When MBDIS is set to logic one, M-bit errors are disabled from causing an OOF; the LOF
criteria is based solely on the number of F-bit errors selected by the M3O8 bit. When MBDIS
is set to logic zero, errors in either M-bits or F-bits are enabled to cause an OOF. When
MBDIS is logic zero, an OOF can occur when one or more M-bit errors occur in three out of
4 consecutive M-frames, or when the F-bit error ratio selected by the M3O8 bit is exceeded.
FDET
The FDET bit selects the fast detection timing for AIS, IDLE and RED. When FDET is set to
logic one, the AIS, IDLE, and RED detection time is 2.23 ms; when FDET is set to logic
zero, the detection time is 13.5 ms.
AISPAT
The AISPAT bit controls the pattern used to detect the AIS (AIS). When a logic one is written
to AISPAT, the AIS detection algorithm checks that a framed DS3 signal containing the
repeating pattern 1010.. is present. The C-bits are checked for the value specified by the AISC
bit setting. When a logic zero is written to AISPAT, the AIS detection algorithm is determined
solely by the settings of AISC and AISONES register bits (see bit mapping table in the
Additional Configuration Register description).
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
127
PMC [ PMC-SIERRA, INC ]
