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STANDARD PRODUCT
PM7323 RCMP-200
DATASHEET
PMC-960543
ISSUE 2
ROUTING CONTROL, MONITORING, & POLICING
200 MBPS
Proprietary and Confidential to PMC-Sierra, Inc.
and for its Customer’s Internal Use.
39
MSB
SD[39:34]
LSB
SD[33]
Left
Leaf
SD[32:17]
Left Branch
SD[16]
Right
Leaf
SD[15:0]
Right Branch
Select
Select
The index of the Secondary Search Key bit upon which the
branching decision is based. An index of zero represents
the LSB. If the selected bit is a logic one, the "Left Leaf" and
"Left Branch" fields are subsequently used. Likewise, if the
selected bit is a logic zero, the "Right Leaf" and "Right
Branch" are subsequently used. Typically, the Select value
decreases monotonically with the depth of the tree, but other
search sequences are supported by the flexibility of this bit.
If a VC belongs to a multicast, the select field is set to an all
ones pattern, except the last in the linked list. For a
multicast entry, the Left_Branch gives the VC table address
of the multicast VC (the Left Leaf is always '1'). The
Right_Branch points to the Search Table address of the next
VC in the multicast. The VC search table therefore forms a
linked list and may multicast an arbitrary number of cells.
The linked list is terminated by setting the Select field to
value that is not all ones. A non all ones value in the Select
field instructs the search engine that the Left_Branch field
provides the final VC Search Table Address of the multicast
set.
Left Leaf
This flag indicates if this node is a leaf. If "Left Leaf" is a
logic one, the left branch is a leaf and the binary search
terminates if the decision bit is a logic one. If "Left Leaf" is a
logic zero, "Left Branch" value points to another node in the
binary tree.
If the VC pointed to by the Left Branch is the first VC in a
multicast set, the Left_Leaf must be set to a logic 1. For the
remaining VCs in the multicast set, the Left Leaf value is
arbitrary, but it is recommended to be set to a logic 1 for
future compatibility.
Left Branch
The pointer to the node accessed if the decision bit is a logic
one. If "Left Leaf" is a logic one, "Left Branch" contains the