Patent ID: 7716416

Claim:
A content-addressable-memory device, comprising: a tag storing unit that stores a plurality of entries, each entry including a tag corresponding to an address, a parity bit of the tag, and a reverse bit obtained by reversing the parity bit; a data storing unit that stores data corresponding to each entry; a comparing unit that compares a search address with the tag of each of the entries to find any plurality of matching entries, each with a matching tag that matches the search address, as a multi-hit occurrence; and a determining unit that performs an OR-operation on the matching entries when the comparing unit finds the matching entries as the multi-hit occurrence, and determines a cause of the multi-hit occurrence based on a result of the OR operation for the parity bit and a result of the OR operation for the reverse bit, by determining the cause of the multi-hit occurrence to be a parity error if the result of the OR operation for the parity bit is equal to the result of the OR operation for the reverse bit and determining the cause of the multi-hit occurrence not to be the parity error if the result of the OR operation for the parity bit is not equal to the result of the OR operation for the reverse bit.