Proprietary and Confidential to PMC-Sierra, Inc and for its Customers
’
Internal Use
Document ID: PMC-2010146, Issue 4
140
PM2329 ClassiPI Network Classification Processor Datasheet
5.1.4 Rule Attribute Bit
Each PM2329 Rule contains a Rule Attribute Bit. This bit does not participate in Rule processing
operations; it is intended for use by the external processor. When a particular rule matches, the match result
will contain the Attribute Bit taken from the rule that matched. This provides an additional degree of
flexibility for the external processor software when handling match results.
5.1.5 Rule Negation
The PM2329 performs operations between various data sub-fields of the rule and packet data as described
earlier, and returns a combined result of this operation. The Rule Negation bit allows the returned result to
be negated. For example, if this bit is set to
‘
0
’
and an equality check is performed between rule and data
sub-fields and the packet and rule data are equal, the result will indicate a match condition. However, if this
bit is set to '1' for the same example, the result will indicate a
“
no match
”
condition.
5.2 Operation Cycles
The
Operation Cycle
(
OC)
is the basic classification operation performed by the PM2329 on the data
extracted from a packet. It consists of comparing a string of extracted data against a set of rules and
returning the relative offset of the rule that matched (single-hit OC), or a set of relative offsets of rules that
matched (multi-hit OC).
OCs specify the set of rules on which the OC will be executed (also called the Rule Partition) and the type
of extracted packet data that will be classified (also known as the Data Source).
The Rule Partition defines a subset of the Policy Database that will be used during the execution of an OC.
The Policy Database is organized with a total of 16 columns and 64 rows. Each column is further made up
of 16 rule cells. A Rule Partition is defined by two sets of values:
a)
The set of columns containing the rules, and
b)
The set of rows containing the rules within the partition.
For a given Rule Partition, individual columns (between 1 and 16, in any combination) can be specified.
The rows of a Rule Partition must be defined with a start and end row (both inclusive). Given this
definition scheme, note that the columns of the partition need not be contiguous, whereas the rows within a
column will always be contiguous. The minimum partition granulariy permitted by this scheme is 16 rule
cells (a single row of a single column) and the maximum is the entire Policy Database rule memory in the
device. The number of rule cells in a Rule Partition will always be a multiple of 16.