PM5363 TUPP+622
TUPP+622
DATASHEET
PMC-1981421
ISSUE 4
SONET/SDH TRIBUTARY UNIT PAYLOAD PROCESSOR FOR 622 MBIT/S
INTERFACES
and expected messages match. An accepted message that contains all-zero
bytes is treated specially. If the expected messages is not also all-zeros, the TIM
alarm is not affected upon accepting of an all-zero message. If the expected
message is all-zeros, accepting an all-zeros message would negate TIM.
The alarm monitor block also monitors the incoming messages for stability. Two
algorithms are provided. In the first algorithm, each time the current incoming
message differs from the previous message, the corresponding unstable counter
is incremented by one. Thus, a single bit error in a message of a sequence of
constant messages will cause the counter to increment twice, once on the
corrupted message, and again on the first error free message. A trail trace
identifier unstable (TIU) alarm is raised when the counter exceeds the register
programmable threshold. The counter is cleared and TIU negated when a set of
identical messages is received and becomes the accepted message. In the
second algorithm, when the current incoming message differs from the previous
message, the corresponding counter starts incrementing once per message. A
trail trace identifier unstable (TIU) alarm is raised when the counter exceeds the
register programmable threshold. The counter is cleared and TIU negated when
a set of identical messages is received and becomes the accepted message.
10.5.5 Buffer
The buffer block contains two pages of memory, one page for capturing the
receive tributary path trace messages and the other for storing the expected
messages. Each tributary in the incoming stream is allocated a range of
addresses using high order interleaving keyed on the tributary group number and
the tributary number within the group. At the J2 byte (J1 byte in TU3 mode) of
each tributary, the receive and expected pages are read. The data from the
incoming stream, the receive page and the expected page are supplied to the
alarm monitor block for determination of trace identifier mismatch (TIM) and trace
identifier unstable (TIU) alarms. At the end of the cycle, the incoming data is
written to the receive page. The buffer block also contains an arbiter to allow
access to the receive and expected pages by the microprocessor when neither
the extract nor alarm monitor block requires access.
10.6 JTAG Test Access Port
The JTAG Test Access Port block provides JTAG support for boundary scan. The
standard JTAG EXTEST, SAMPLE, BYPASS, IDCODE and STCTEST
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
106
PMC [ PMC-SIERRA, INC ]
