Takahiro Kawata

A design for a minimum Hamming-distance search using asynchronous digital techniques

An approach for a completely static and digital implementation of a minimum Hamming-distance search is presented in this paper. A newly developed associative memory performs the search operation by executing a bubble sort operation for a binary data, which we call a bubble shift, with the assistance of three kinds of replica signals generated from a replica word and bit scheme. The bubble shift operation is achieved with a bit swap cell which swaps its own value with neighboring cells asynchronously and in parallel. This concentration of asynchronous techniques used in the memory allows for a 35-ns search-time for a 64 word /spl times/ 128 bit macro with 0.13-/spl mu/m 7-layer CMOS process.

A digital circuit for a minimum distance search using an asynchronous bubble shift memory

The architecture described allows a fully digital circuit to search for the minimum Hamming distance. It compares favorably with prior approaches in its robustness and short design time. A concentration of asynchronous circuit techniques allows a 35 ns search time of 64 entry/spl times/128 bit data with a 0.13 /spl mu/m 5M CMOS process.