A mixed digital-analog SIMD chip tailored for image perception

摘要

A SIMD machine made of a 2D array of mixed analog-digital cells is described. Communication with the SIMD machine is tailored to be coupled both with imagers through the use of a scanner and with low level vision chips through an address bus encoding activity in pulse frequency. The digital part of a cell works on 4-bit words. A cell contains an ALU, 6 words of memory, 2 flags, a spatial analog filter connecting to the 8 neighbours to perform low or high-pass spatial filtering of the image, 9 analog multipliers for a weighted summation by a 3 by 3 kernel, an A/D converter and a D/A converter. A cell can communicate with its 8 neighbours through analog or digital links. Instructions can be masked locally allowing processing depending on local results. Each cell contains about 1040 transistors and is 235 /spl mu/m by 215 /spl mu/m in a 0.5 /spl mu/m CMOS process.