PM7347 datasheet(127/341 Pages) PMC

127 / 341 page

S/UNI®-JET Data Sheet

Released

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

127

Document ID: PMC-1990267, Issue 3

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).

PM7347 Datasheet(PDF) 127 Page - PMC-Sierra, Inc