PM5364 pmc-sierra, PM5364 Datasheet - Page 96

• 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
Pointer Interpreter
The function of the pointer interpreter is to extract and validate the pointer from the H1/H2
bytes in order to identify the location of the path trace byte (J1) and all the synchronous payload
envelop (SPE) bytes of the constituent STS (VC) payloads. The pointer interpreter is a time-
multiplexed finite state machine that can process any legal mix of STS-1/3c/12c (AU3/4/4-4c)
pointers. The H1 and H2 bytes can be viewed as one word as shown in Figure 17.
Figure 17 Payload Pointers (H1, H2) Coding
Within the pointer interpretation algorithm 3 states are defined as shown below:
•
•
•
The transitions between the states will be consecutive events (indications), for example, 3
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 behaviour 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 an NDF enabled with a valid pointer value. It is implied that
since the algorithm only contains transitions based on consecutive indications, non-
consecutively received invalid indications do not activate the transitions to the LOP_state for
example.
N N N N s s
1 2 3 4 5 6 7 8
NORM_state (NORM)
AIS_state (AIS)
LOP_state (LOP)
Bit Assignments:
I - Increment
D - Decrement
N - New Data Flag
s - ss bits (Undefined in Bellcore)
H1
I D
1 2 3 4 5 6 7 8
I D I D I D I D
10-bit Pointer
H2
TUPP™ 2488 ASSP Telecom Standard Product Data Sheet
Opportunity Byte
Negative Stuff
H3
Opportunity Byte
Positive Stuff
Released
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