PM8610-BIAP PMC [PMC-Sierra, Inc], PM8610-BIAP Datasheet - Page 75

• Manufacturer Part Number: PM8610-BIAP
• Description: SBS Telecom Standard Product Data Sheet Preliminary
• Manufacturer: PMC [PMC-Sierra, Inc]

10.7
10.7.1
10.7.2
10.8
10.8.1
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000168, Issue 3
PRBS Processors
The Working and Protection PRBS Processor blocks, WPP and PPP, provides in-service and off-
line PRBS generation and detection for diagnostics of the equipment downstream of the two
LVDS links. Each PRBS Processor has the capacity to source and monitor PRBS data for the
associated Working or Protection Serial SBI336S stream with a granularity of unchannelized SBI
SPEs of TelecomBus STS-1s.
The PRBS generator sub-block optionally overwrites the data originating from the incoming data
streams, IDATA[4:1][7:0]. When enabled, the PRBS generator sub-block inserts synchronous
payload envelope, SPE bytes into the serial transmit links. The inserted data is derived from an
internal linear feedback shift register (LFSR) with a polynomial of X
The PRBS detector sub-block monitors the synchronous payload envelope, SPE, bytes in the
incoming data stream. The incoming data is compared against the expected value derived from
an internal linear feedback shift register (LFSR) with a polynomial of X
incoming data fails to match the expected value for three consecutive bytes, the PRBS detector
sub-block will enter out-of-synchronization (OOS) state. The LFSR will be re-initialized using
the incoming data bytes. The new LFSR seed is confirmed by comparison with subsequent
incoming data bytes. The PRBS detector sub-block will exit the OOS state when the incoming
data matches the LFSR output for three consecutive bytes. The PRBS detector sub-block will
remain in the OOS state and re-load the LFSR if confirmation failed. The PRBS sub-block
counts PRBS byte errors and optionally generates interrupts when it enters and exits the OOS
state.
Transmit 8B/10B Encoders
The Transmit 8B/10B Encoder blocks, TW8E and TP8E, construct an 8B/10B character stream
from an incoming translated SBI336 bus or TelecomBus carrying an STS-12/STM-4 equivalent
stream.
In SBI mode, these blocks encode the SBI336S stream as shown in Table 21. When configured
for Synchronous mode for DS0 switching, the 8B/10B encoder transmits CAS signaling
multiframe alignment across the SBI336S interface by generating a C1FP character every 48
frame times. When not configured for DS0 switching the C1FP character is sent every 4 frames.
Table 21 shows the mapping of SBI336S bus control bytes and signals into 8B/10B control
characters. The linkrate octet in location V4, V1 and V2, the in-band programming channel, the
V3 octet when it contains data are all carried as data. Justification requests for master timing are
carried in the V5 character so there are three V5 characters used, nominal, negative timing
adjustment request, positive timing adjustment request.
PRBS Generator
PRBS Detector
SBI336S 8B/10B Character Encoding
SBS Telecom Standard Product Data Sheet
23
+ X
23
+ X
18
+ 1.
18
+ 1. If the
Preliminary
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