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STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
PROPRIETARY AND CONFIDENTIAL
130
DS0s, but only if the SBI interface is configured for synchronous mode
operation.
9.41 Insert Scaleable Bandwidth Interconnect (INSBI)
The Insert Scaleable Bandwidth Interconnect block maps up to 28 1.544Mb/s
links, 21 2.048Mb/s links or a single 44.736Mb/s link into the SBI shared bus.
The 1.544Mb/s links can be unframed when sourced directly from the DS3
multiplexer or SONET/SDH mapper, or they can be T1 channelized when
sourced by the T1 framers. The 2.048Mb/s links can be unframed when sourced
directly from the SONET/SDH mapper, or they can be E1 channelized when
sourced by the E1 framers. The 44.736Mb/s link can also be unframed when
sourced directly from the DS3 interface or from the DS3 mapper. The
44.736Mb/s link can be an unchannelized DS3 when sourced from the DS3
framer.
Links inserted into the SBI bus can be timed from the TEMUX or from the far
end. The INSBI makes link rate adjustments by adding or deleting an extra byte
of data over a 500uS interval based on buffer fill levels. Timing adjustments
made by the INSBI are detected by the receiving SBI interface by explicit signals
in the SBI bus structure.
The INSBI optionally sends link rate information across the SBI bus. This
information is used by the receiving SBI interface to create a recovered link clock
which is based on small clock phase adjustments signaled by the INSBI.
Channelized T1s inserted into the SBI bus optionally have the channel
associated signaling (CAS) bits explicitly defined and carried in parallel with the
DS0s or timeslots, but only if the SBI interface is configured for synchronous
mode operation. When enabled for CAS insertion the INSBI takes a byte serial
stream of CAS bits from the SBISIPO and inserts them into the SBI bus
structure.
9.42 Scaleable Bandwidth Interconnect PISO (SBIPISO)
The Scaleable Bandwidth Interconnect Parallel to Serial converter (SBIPISO)
generates up to 28 T1s, 21 E1s or a DS3 serial clock and data signals from the
byte serial stream provided by the Extract SBI block. The generated clock rate
can be controlled with commands from the EXSBI. In clock slave mode the
generated clock will be increased or decreased in small increments based on
FIFO fill levels within the EXSBI or directly with clock rate commands from the far
end device who is mastering the clock across the SBI bus. In clock master mode
the SBIPISO controls the bit rate by accepting data from the EXSBI at the rate of
the individual T1, E1 or DS3 clocks sourced into it.