Cisco Systems, Inc.
Coordinated updating and searching a content-addressable memory including for packet processing operations

Abstract:

In one embodiment, updating and searching of entries in a hardware content-addressable memory is coordinated to provide more searching bandwidth (e.g., for determining packet processing information), including, but not limited to, when vectors are moved among entries to free up desired entry positions for insertion of other vectors. A lookup operation is performed in content-addressable memory entries in a hardware content-addressable memory based on a lookup word to generate a content-addressable memory lookup result. Typically overlapping in time, a matching operation is performed in one or more transitory entries to generate a transitory matching result based on the lookup word. These transitory entries are populated with transitory vectors and have an associated index within the content-addressable memory, with these transitory vectors are subsequently inserted in the content-addressable memory at their associated index positions. A matching result is determined from the content-addressable memory lookup result and the transitory matching result.