Address range checking circuit and method of operation

摘要

There is disclosed an address range checking circuit capable of determining if a target address, A[M:0], is within an address space having 2^N address locations beginning at a base address location, B[M:0], wherein the address range checking circuit does not require a large comparator circuit. The address range checking circuit comprises: 1) comparison circuitry for determining if the address segment A[N-1:0] is less than the address segment B[N-1:0] and generating on a first control signal; 2) first equivalence detection circuitry for determining if the address segment A[M:N] is equal to the address segment B[M:N] and generating an A=B status signal; 3) second equivalence detection circuitry for determining if the address segment A[M:N] is equal to the address segment B[M:N] plus one and generating an A=B+1 status signal; and 4) a multiplexer that outputs the A=B status signal or the A=B+1 status signal depending on the value of the first control signal.