PM5364 pmc-sierra, PM5364 Datasheet - Page 115

• Manufacturer Part Number: PM5364
• Description: Tupp 2488 Assp Telecom Standard
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2011334, Issue 7
A persistent trail trace identifier is declared when an identical identifier is received for 3 or 5
consecutive multiframes, as configured by the PER5 register bit. When the NOSYNC register
bit is logic 0, a trail trace identifier can only be declared persistent if it is appropriately
synchronized via CR/LF characters or the TFAS. When the NOSYNC register bit is logic 1, trail
trace identifiers without synchronization can be declared persistent. In the special case where
NOSYNC is logic 0 and ZEROPGEN is logic 1, all zeros messages can be declared persistent.
A persistent trail trace identifier becomes the accepted trail trace identifier. The accepted
identifier is stored in the accepted page.
A trail trace identifier mismatch (TIM) is declared when the accepted identifier does not match
the expected identifier. A TIM is removed when the accepted identifier matches the expected
message. When the ZEROPGEN register bit is asserted, all zeros messages are given special
consideration: TIM is declared when the accepted identifier is neither all zeros nor a match to
the expected identifier; TIM is removed when the accepted identifier is either all zeros or a
match to the expected identifier. An interrupt is optionally generated upon a change in the TIM
state. The expected identifier is a static identifier written in the expected page by an external
microprocessor.
An unstable trail trace identifier (TIU) is declared when one or more erroneous bytes are
detected between the current received identifier and the previous received identifier in a total of
8 or 127 trail trace identifiers without an intervening persistent message. A TIU is removed
when a persistent message is received. An interrupt is optionally generated upon a change in the
TIU state.
The TIM algorithms contain other features as well. First, both algorithms are robust in the
presence of bit errors. Second, in Algorithm 1, a change in the phase of the incoming J2 byte
causes only one sample to be mismatched for the purposes of detecting TIM (a change of phase
could be caused, for example, by upstream protection switches causing one or more J2 bytes to
be dropped or repeated). Third, monitoring of TIM and TIU can be suspended via the
SUSPEND function. SUSPEND is optionally enabled when the J2 byte becomes inaccessible
(e.g., when a Loss Of Pointer or Alarm Indication Signal defect has been detected). SUSPEND
is controlled via top-level registers to be a logical OR of any combination of the following
alarms from the VTPI: LOM, Tributary LOP, Tributary AIS, Path AIS.
Note
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The terms “tributary trace message,” “trail trace identifier,” and “trail trace message,” are used
interchangeably in this document.
TUPP™ 2488 ASSP Telecom Standard Product Data Sheet
Released
115