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PM7329 S/UNI-APEX-1K800
DATASHEET
PMC-2010141
ISSUE 2
ATM TRAFFIC MANAGER AND SWITCH
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
153
14
MEMORY PORT MAPPING
14.1 Context Size and Location
The context records for S/UNI-APEX-1K800 are stored in 4 different areas. The
majority of the context information is stored in an external SSRAM, the context
memory. For performance reasons, some context information is stored in
internal memories. There are three internal memories, the Queue context, the
WAN Port scheduler context, and the Loop Port scheduler context
Figure 29
- Context Location
Internal
Queue
Context
Loop Class Scheduler
Loop Port Threshold
Loop Port Count
WAN Class0
WAN Class1
WAN Class2
WAN Class3
WAN Class Scheduler
WAN Port Threshold
WAN Port Count
uP Class Scheduler
uP Port Threshold
uP Port Count
uP Class0
uP Class1
uP Class2
uP Class3
Free Count
Overall Count
Congestion Discard
Max Congestion ID
Misc Error
External
Queue
Context
Memory Port
Aperture Select
VC Context
VC Statistic
VC Address Map
Loop Class0
Loop Class1
Loop Class2
Loop Class3
Shape0 TxSlot
Shape1 TxSlot
Shape2 TxSlot
Shape3 TxSlot
Shape Rate
Cell
QCellStartAdr
Address 0
QLClassStartAdr
QShpStartAdr
Internal
Loop Port Scheduler
Context
Loop Poll Sequence
Loop Poll Weight
Loop Class Status
Internal
WAN Port Scheduler
Context
WAN Poll Weight
WAN Class Status
The records for the external context memory are partitioned into four groups: VC,
Loop Ports, Shape and Cells. Three registers define the starting physical
address of each of the Loop class, Shape and Cell groups, with the VC group
always starting at address zero.
The starting address, or offset, may be of any order, and may, under certain
restriction, overlap one another. For example, if the VC Address Map will never
be enabled for a given application, then the loop class offset may be set to the