Patent ID: 7526603

Claim:
An apparatus for routing address lookup in a router, comprising of at least one monolithic integrated device, each comprising: (a) a plurality of content addressable memory banks for storing and looking up the routing addresses, (b) at least one bank-level content comparing memory array for each content addressable memory bank, said bank-level content comparing memory array or arrays storing the numerical range of the routing addresses in the corresponding content addressable memory bank, allowing for numerical range check to be done for each content addressable memory bank, (c) first means for interpreting the contents of said bank-level content comparing memory array or arrays for deciding whether the search address is in the corresponding content addressable memory bank, (d) second means for connecting said bank-level content comparing memory array or arrays to said content addressable memory bank and for activating said content addressable memory bank based on the interpretation of said first means, whereby, said content addressable memory banks are deterministically divided into classes based on the numerical ranges of the routing addresses, and any particular memory bank of said content addressable memory banks is only activated if said search address is known to be in that memory bank's stored routing address range, which saves the power consumed by the apparatus.