A mixed-signal array processor with early vision applications

摘要

Many early vision tasks require only 6 to 8 b of precision. Fornthese applications, a special-purpose analog circuit is often a smaller,nfaster, and lower power solution than a general-purpose digitalnprocessor, but the analog chips lack the programmability of digitalnimage processors. This paper presents a programmable mixed-signal arraynprocessor which combines the programmability of a digital processor withnthe small area and low power of an analog circuit. Each processor cellnin the array utilizes a digitally programmable analog arithmetic unitnwith an accuracy of 1.3%. The analog arithmetic unit utilizes a uniquencircuit that combines a cyclic switched-capacitor analog-to-digitalnconverter (ADC) and digital-to-analog converter (DAC) to performnaddition, subtraction, multiplication, and division, Each processorncell, fabricated in a 0.8-Μm triple-metal CMOS process, operates at anspeed of 0.8 MIPS, consumes 1.8 mW of power at 5 V, and uses 700 Μmnby 270 Μm of silicon area. An array of these processor cellsnperformed an edge detection algorithm and a subpixel resolutionnalgorithm