A Minimum Distance Search Circuit using Dual-Line PWM Signal Processing and Charge Packet Counting Techniques

This CMOS minimum distance search circuit (MDS) realizes pattern matching engines for multi-media and intelligent processing systems. The chip executes highly-parallel computation of Manhattan distances between an input vector and stored multiple reference vectors, and search of the minimum distance among them. Two novel circuit techniques are based on pulse width modulation (PWM) analog-digital merged circuits.