Method and device for determining hamming distance between two multi-bit

Abstract

A Hamming distance calculation device (10) includes a bit comparator (12) for determining nonmatching bit positions between two digital words. A current signal is generated for each nonmatching bit position by a nonmatching current generator (14). The current signals created are combined to produce a summed current signal that drives a first reference current comparator (18), a second reference current comparator (20), and an nth reference current comparator (22). The first reference current comparator (18) compares the summed current signal with a reference current signal to produce an output and a select signal that determines a reference current signal used in the second reference current comparator (20). The second reference current comparator (20) compares the summed current signal with a reference current signal as selected by the first reference current comparator (18) and produces an output in response thereof. The Nth reference current comparator (22) compares the summed current signal with a reference current signal as selected by the previous reference current comparator (20) and produces an output in response thereof. Each reference current comparator provides an output that collectively establish a digital output word indicating the Hamming distance between the two input digital words.