STANDARD PRODUCT
PM4328 TECT3
DATASHEET
PMC-2011596
ISSUE 1
HIGH DENSITY T1/E1 FRAMER
AND M13 MULTIPLEXER
12.10 SBI Bus Data Formats
The TECT3 uses the Scaleable Bandwidth Interconnect (SBI) bus as a high
density link interconnect with devices processing T1s and DS3s. The SBI bus is
a multi-point to multi-point bus capable of interconnecting up to three TECT3
devices in parallel with other link layer or tributary processing devices.
Multiplexing Structure
The SBI structure uses a locked SONET/SDH structure fixing the position of the
TU-3 relative to the STS-3/STM-1. The SBI is also of fixed frequency and
alignment as determined by the reference clock (SREFCLK) and frame indicator
signal (SC1FP). Frequency deviations are compensated by adjusting the
location of the T1/DS3 channels using floating tributaries as determined by the
V5 indicator and payload signals (SDV5, SAV5, SDPL and SAPL).
Table 11 shows the bus structure for carrying T1 and DS3 tributaries in a SDH
STM-1 like format. Up to 84 T1s or 3 DS3s are carried within the octets labeled
SPE1, SPE2 and SPE3 in columns 16-270. All other octets are unused and are
of fixed position. The frame signal (SC1FP) occurs during the octet labeled C1
in Row 1 column 7.
The multiplexed links are separated into three Synchronous Payload Envelopes
called SPE1, SPE2 and SPE3. Each envelope carries up to 28 T1s or a DS3.
SPE1 carries the T1s numbered 1,1 through 1,28 or DS3 number 1,1. SPE2
carries T1s numbered 2,1 through 2,28 or DS3 number 2,1. SPE3 carries T1s
numbered 3,1 through 3,28 or DS3 number 3,1. The most significant bit in all
formats is the first bit of transmission.
PROPRIETARY AND CONFIDENTIAL
157
PMC [ PMC-SIERRA, INC ]
