PM5345 S/UNI-155
DATA SHEET
PMC-930305
ISSUE 4
SATURN USER NETWORK INTERFACE
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DESCRIPTION
The PM5345 S/UNI SATURN User Network Interface is a monolithic integrated
circuit that implements the SONET/SDH processing and ATM mapping functions
of a 155 Mbit/s ATM User-Network Interface.
The S/UNI receives SONET/SDH frames, via a bit serial or byte serial interface,
and processes section, line, and path overhead. It performs framing (A1, A2),
descrambling, detects alarm conditions, and monitors section, line, and path bit
interleaved parity (B1, B2, B3), accumulating error counts at each level for
performance monitoring purposes. Line and path far end block error indications
(Z2, G1) are also accumulated. The S/UNI interprets the received payload
pointers (H1, H2) and extracts the synchronous payload envelope which carries
the received ATM cell payload. In addition to its basic processing of the received
SONET/SDH overhead, the S/UNI provides convenient access to all overhead
bytes, which are extracted and serialized on lower rate interfaces, allowing
additional external processing of overhead.
The S/UNI frames to the ATM payload using cell delineation. HCS error
correction is provided. Idle/unassigned cells may be dropped according to a
programmable filter. Cells are also dropped upon detection of an uncorrectable
header check sequence error. The ATM cell payloads are descrambled. The
ATM cells that are passed are written to a four cell FIFO buffer. The received
cells are read from the FIFO using a generic 9 bit wide or 17 bit wide datapath
interface. Counts of received ATM cell headers that are errored and
uncorrectable and also those that are errored and correctable are accumulated
independently for performance monitoring purposes.
The S/UNI transmits SONET/SDH frames, via a bit serial or a byte serial
interface, and formats section, line, and path overhead appropriately. It performs
framing pattern insertion (A1, A2), scrambling, alarm signal insertion, and
creates section, line, and path bit interleaved parity (B1, B2, B3) as required to
allow performance monitoring at the far end. Line and path far end block error
indications (Z2, G1) are also inserted. The S/UNI generates the payload pointer
(H1, H2) and inserts the synchronous payload envelope which carries the ATM
cell payload. In addition to its basic formatting of the transmitted SONET/SDH
overhead, the S/UNI provides convenient access to all overhead bytes, which are
optionally inserted from lower rate serial interfaces, allowing external sourcing of
overhead. The S/UNI also supports the insertion of a large variety of errors into
the transmit stream, such as framing pattern errors, bit interleaved parity errors,
and illegal pointers, which are useful for system diagnostics and tester
applications.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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PMC [ PMC-SIERRA, INC ]
