STANDARD PRODUCT
PM5365 TEMAP
DATASHEET
PMC-1991148
ISSUE 3
HIGH DENSITY VT/TU MAPPER
AND M13 MULTIPLEXER
frame (or G.747 frame, depending upon the framing format selected) is said to
be a "valid" interval if it contains a RED defect, defined as the occurrence of an
OOF event during that M-frame (or G.747 frame). For AIS, a DS2 M-frame (or
G.747 frame) is said to be a "valid" interval if it contains AIS, defined as the
occurrence of less than 9 zeros while the framer is out of frame during that M-
frame (or G.747 frame). The discrepancy threshold ensures the detection
algorithm operates in the presence of bit error rates of up to 10-3. Each "valid"
DS2 M-frame (or G.747 frame) causes an integration counter to increment; "non-
valid" DS2 M-frame (or G.747 frame) intervals cause a decrement. RED or AIS
is declared if the associated integrator count saturates at 53, resulting in a
detection time of 9.9 ms for DS2 and 6.9 ms for G.747. RED or AIS declaration
is deasserted when the associated count decrements to 0.
The DS2 X-bit or G.747 remote alarm indication (RAI) bit is extracted by the DS2
FRMR to provide an indication of far end receive failure. The FERF status is set
to the current X/RAI state only if the two successive X/RAI bits were in the same
state. The extracted FERF status is buffered for 6 DS2 M-frames or 6 G.747
frames before being reported within the DS2 FRMR Status register. This buffer
ensures a virtually 100% probability of freezing the FERF status in a valid state
during an out of frame occurrence in DS2 mode, and ensures a better than
99.9% probability of freezing the valid status during an OOF occurrence in G.747
mode. When an OOF occurs, the FERF value is held at the state contained in
the last buffer location corresponding to the previous sixth M-frame or G.747
frame. This location is not updated until the OOF condition is deasserted.
Meanwhile, the last four of the remaining five buffer locations are loaded with the
frozen FERF state while the first buffer location corresponding to the current M-
frame/ G.747 frame is continually updated every M-frame/G.747 frame based on
the above FERF definition. Once correct frame alignment has been found and
OOF is deasserted, the first buffer location will contain a valid FERF status and
the remaining five buffer locations are enabled to be updated every M-frame or
G.747 frame.
DS2 M-bit and F-bit framing errors are indicated as are G.747 framing word
errors (or bit errors) and G.747 parity errors. These error indications are
accumulated for performance monitoring purposes in internal, microprocessor
readable counters. The performance monitoring accumulators continue to count
error indication even while the framer is indicating OOF.
The DS2 FRMR may be configured to generate interrupts on error events or
status changes. All sources of interrupts can be masked or acknowledged via
internal registers. Internal registers are also used to configure the DS2 FRMR.
Proprietary and Confidential to PMC-Sierra, Inc. and for its Customers’ Internal Use
79
PMC [ PMC-SIERRA, INC ]
