PM5364 pmc-sierra, PM5364 Datasheet - Page 130

• Manufacturer Part Number: PM5364
• Description: Tupp 2488 Assp Telecom Standard
• Manufacturer: pmc-sierra

10.7.2
10.7.3
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2011334, Issue 7
The MSU-Lite also supports an overwrite mode where columns can be configured with specific
overwrite modes. When enabled these modes generate the output stream based on the per
column configuration stored in the Switch Control RAM. The overwrite modes are active when
the switch control RAM value is out of range (i.e. IN_BYTE(13:12) = 11b). The overwrite
modes allow output streams (VT/TU or STS-1/STM-0 level) to be configured to generate
outputs such as Unequipped tributaries, generate tributary or path level indicators such as V5
and J1 on the output stream. For further details see Table 38. V5 and TPL overwrite have no
effect in the egress path.
Column Cross Bar Switch (CCB)
The CCB block is central to TUPP 2488 in performing column granularity space switching on
16 STS-12 77.76 MHz TelecomBuses. The CCB functions as an STS-192/STM-64 cross bar
and allows for hair-pinning and OC-48 ADM functionality (with 1-2 multicasting).
At every clock cycle of the 77.76 MHz clock the CCB switches a byte of data and its associated
controls from one of the input ports to an output port. This mapping is software configured in
the connection memory page. The switched information may be one byte of a column
comprising a VT1.5, VT2, VT3, VT6, or STS-1.
The 16 input buses to CCB must be synchronized (i.e. J0 frame aligned) in order for switching
to take place.
Configuration settings for the outputs are stored in two pages of connection memory that are
software accessible. Each page of RAM maps all 16 outputs from an input in a 1080 byte row.
The dual page configuration architecture allows configuration changes to the offline page to
take place while the device is reading from the active page to support hitless switching. When
configuration updates are complete, pages are swapped on the next frame boundary.
The CCB supports a bypass mode in which no switching is done. This is configured so that
when the CCB is placed in bypass mode, the eight STS-12 streams from the line ingress path
are passed through the CCB to the eight system ingress STS-12 streams, and the eight system
egress STS-12 streams are passed through the CCB to the line egress path.
Switch Fabric Subsystem Logic
The subsystem logic implements the following functions:
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J0 control
CMP control
Bi-Cast multiplexing
Loopback logic
Reset control logic
TUPP™ 2488 ASSP Telecom Standard Product Data Sheet
Released
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