Multi-level content addressable memory
AssigneeMcData Corporation
InventorsJeremy Branscome, Michael Corwin
Life of this patent
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Abstract
A multi-level content addressable memory (CAM) architecture compresses out much of the redundancy encountered in the search space of a single CAM, particularly for flow-based lookups in a network. Destination and source address may be associated with internal equivalence classes independently in one level of the multi-level CAM architecture, while flow-specific properties linking arbitrary classes of the destination and source addresses may be applied in a later level of the multi-level CAM.
Claims20
A multi-level content addressable memory comprising:
- a first content addressable memory module that receives a search key of a first search type and outputs a first search result reference;
- a second content addressable memory module that receives a search key of a second search type and outputs a second search result reference;
- and
- an output content addressable memory coupled to receive the first search result reference from the first content addressable memory module and the second search result reference from the second content addressable memory module, wherein the output content addressable memory outputs an output search result based on the first search result reference and the second search result reference.
A method for processing data using a multi-level content addressable memory comprising:
- receiving a search key of a first search type in a first content addressable memory module;
- outputting a first search result reference from the first content addressable memory module, based on the search key of the first search type;
- receiving a search key of a second search type in a second content addressable memory module;
- outputting a second search result-reference from the second content addressable memory module, based on the search key of the second search type;
- outputting an output search result from output content addressable memory based on the first search result reference and the second search result reference, wherein the output content addressable memory is coupled to receive the first search result reference from the first content addressable memory module and the second search result reference from the second content addressable memory module.
A network communications device comprising:
- a multi-level content addressable memory including
- a first content addressable memory module that receives a search key of a first search type and outputs a first search result reference;
- a second content addressable memory module that receives a search key of a second search type and outputs a second search result reference;
- and
- an output content addressable memory coupled to receive the first search result reference from the first content addressable memory module and the second search result reference from the second content addressable memory module, wherein the output content addressable memory outputs an output search result based on the first search result reference and the second search result reference.
Dependencies are inferred from the claim text.