Patent ID: 7552275

Claim:
In a packet switching device or system, a method of performing a table lookup operation using a table lookup index, the method comprising: performing a first CAM access to a first CAM system using a first CAM key of a first type derived from a subset of the table lookup index, resulting in one or more first CAM entries, at least one of said one or more first CAM entries having a first predetermined content portion; performing a second CAM access to a second CAM system using a second CAM key of a second type different than the first type derived from a subset of the table lookup index, resulting in one or more second CAM entries, at least one of said one or more second CAM entries having a second predetermined content portion; and determining one or more matching lookup table entries responsive to at least the first predetermined content portion from the one or more first CAM entries and the second predetermined content portion from the one or more second CAM entries; wherein the first and second CAM systems are the same, and the first and second CAM keys are formatted differently as indicated by a type field included in both first and second key formats, with the type field in the first CAM key indicating a first type, and the type field in the second CAM key indicating a second type.