PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 80

• Manufacturer Part Number: PM5381-BI
• Description: ATM UNI, Single Channel ATM PHY Interface for 2488.32Mbps
• Manufacturer: PMC-Sierra, Inc.

10.5
10.5.1
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
A TIM defect is declared when the accepted message does not match the expected message. A
TIM defect is removed when the accepted message matches the expected message. The expected
message is a static message written in the expected page of the RTTP by an external
microprocessor. Optionally, the algorithm declares a match tail trace message when the accepted
message is all zeros.
The third algorithm is not BELLCORE/ITU compliant. The algorithm detects trace identifier
unstable (TIU) on a single continuous tail trace byte. Only TIU is used in the third algorithm. A
TIU defect is declared when one or more erroneous bytes are detected in three consecutive 16
byte windows. The first window starts on the first erroneous byte. A TIU defect is removed
when an identical byte is received for 48 consecutive frames.
A maskable interrupt is activated to indicate any change in the status of trace identifier unstable
(TIU) and trace identifier mismatch (TIM). TIM is always 0.
Receive High Order Path Processor (RHPP)
The Receive High Order Path Processor (RHPP) provides pointer interpretation, extraction of
path overhead, extraction of the synchronous payload envelope (virtual container), and path level
alarm and performance monitoring.
Pointer Interpreter
The pointer interpreter extracts and validates the H1 and H2 bytes in order to identify the location
of the path overhead byte (J1) and the synchronous payload envelop bytes (SPE) of the
constituent STS-48c (VC-16-16c) payloads. The pointer interpreter is a time multiplexed finite
state machine that can process the STS-48c (AU-16-16c) pointer. Within the pointer
interpretation algorithm three states are defined as shown below:
·
·
·
The transition between states will be consecutive events (indications), e.g., three consecutive AIS
indications to go from the NORM_state to the AIS_state. The kind and number of consecutive
indications activating a transition is chosen such that the behavior is stable and insensitive to low
BER. The only transition on a single event is the one from the AIS_state to the NORM_state
after receiving a NDF enabled with a valid pointer value. It should be noted that, since the
algorithm only contains transitions based on consecutive indications, this implies that, for
example, non-consecutively received invalid indications do not activate the transitions to the
LOP_state.
NORM_state (NORM)
AIS_state (AIS)
LOP_state (LOP)
S/UNI-2488 Telecom Standard Product Datasheet
Released
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