PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 120

• Manufacturer Part Number: PM5366-PI
• Description: HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER AND M13 MULTIPLEXER
• Manufacturer: PMC-Sierra, Inc.

PRELIMINARY
DATASHEET
PMC-2010672
9.30 Transmit Tributary Bit Asynchronous Mapper (TTMP)
PROPRIETARY AND CONFIDENTIAL
affect the state of bit 8 of V5 and (if ERDI is set) bit 5 of Z7. The contents of the
SONET/SDH Master Tributary Auxiliary Remote Defect Indication Control
register determine the which alarms affect the state of bit 4 of V5 if not ERDI or
bit 6 of Z7 if ERDI.
Alternatively, the TRAP may also be configured to extract RDI-V, RFI-V and REI-
V from two independent serial remote alarm ports, RADEAST and RADWEST.
In all cases, the RDI-V and RFI-V state will be sent for a minimum of 10
multiframes before changing, unless a higher priority alarm is required.
The TRAP provides selection between the Telecom Drop bus alarms and the two
remote serial alarm ports for the source of remote alarm status on a per-tributary
basis. By default, all three sources are disabled. Tributaries in any of the three
sources of remote alarms can be mapped to arbitrary tributaries in the outgoing
data stream. The mapping is configured through the TRAP Indirect Remote
Alarm Page Address, TRAP Indirect Remote Alarm Tributary Address and TRAP
Indirect Datapath Tributary Data registers. A valid TU designation written via the
TRAP Indirect Datapath Tributary Data register is all that is required to enable
the alarms for the outgoing tributary specified by the TRAP Indirect Remote
Alarm Tributary Address register. Although it is possible to have any subset of
the three sources enabled, it is usual to have only one of the three sources
enabled for a particular tributary.
Each one of three Transmit Tributary Mapper blocks bit asynchronously maps up
to 28 T1 or 21 E1 streams into an STS-1 SPE, TUG3 in a STM-1/VC4 or STM-
1/VC3 payload. The TTMP compensates for any frequency differences between
the incoming individual serial bit rates and the available STS-1 or STM-1/VC3
payload capacity. The asynchronous T1 mapping consists of 104 octets every
500 µs (2 KHz). The asynchronous E1 mapping consists of 140 octets every 500
µs (2 KHz). Refer to the RTDM block for a description of the asynchronous T1
and E1 mappings.
The tributary mapper is a time-sliced state machine which uses a payload buffer
as an elastic store. The T1 or E1 streams are read from the payload buffer, and
mapped into VT1.5 Payloads and VT2 Payloads using bit asynchronous
mapping only.
The Tributary Mapper compensates for phase and frequency offsets using bit
stuffing. A jitter-reducing control loop is used to monitor the Payload Buffer depth
and reduce mapping jitter to 1.0 UI. To reduce mapping jitter even further, a
dither technique is inserted between the control loop and the stuff bit generator
resulting in an acceptable desynchronizer mapping jitter of about 0.3 UI.
ISSUE 1
108
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
AND M13 MULTIPLEXER
PM5366 TEMAP-84