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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
271
Control
Transmit Operation
Receive Operation
ATM cell alignment with the G.832 E3 frame.
Therefore cell delineation must be performed
to locate the ATM cell boundaries.
EM:
Error Monitor, BIP-8
Inserts the calculated BIP-8
by computing even parity
over all transmit bits,
including the overhead bits of
the previous 125 μs frame.
Computes the incoming BIP-8 value over one
125 μs frame. The result is held and compared
against the value in the EM byte of the
subsequent frame.
TR:
Trail Trace
Inserts the 16 byte trail
access point identifier
specified in internal registers.
Extracts the repetitive trail access point
identifier and verifies that the same pattern is
received. Compares the received pattern to the
expected pattern programmed in a register.
MA:
Maintenance and
Adaptation Byte
Inserts the FERF, FEBE,
Payload Type bits, Tributary
Unit Multiframe Indicator bits
and the Timing Marker bit as
programmed in a register or
as indicated by detection of
receive OOF or BIP-8 errors.
Extracts and reports the FERF bit value when
it has been the same for 3 or five consecutive
frames. S/UNI-JET also extracts and
accumulates FEBE occurrences and extracts
the Payload Type, Tributary Unit Multiframe,
and Timing Market indicator bits and reports
them through microprocessor accessible
registers.
NR:
Network Operator Byte
Inserts the Network Operator
byte from the TOH overhead
stream or optionally from the
TDPR. All 8 bits of the
Network Operator byte are
inserted from TOH or from
the TDPR.
Extracts the Network Operator byte and
outputs it on ROH or optionally terminates it in
the RDLC. All 8 bits of the Network Operator
byte are extracted and presented on ROH or to
the RDLC.
GC:
General Purpose
Communication Channel
Inserts the GC byte from the
TOH overhead stream or
optionally from the TDPR
block.
Extracts the GC byte and outputs it on ROH or
optionally terminates it in the RDLC block.
13.7
J2 Frame Format
The S/UNI-JET provides support for the G.704 and NTT J2 frame format. This format can be
extended to allow for direct byte mapping of ATM cells as specified in G.804. The J2 frame
format consists of 789 bits frames each 125 us long, consisting of 96 bytes of payload, two
reserved bytes, and five F-bits. The frames are grouped into five frame multiframes as shown in
Figure 15.