A CCD programmable image processor and its neural network applications

A charge coupled device (CCD)-based image processor that performs 2D filtering of a gray-level image with 20 programmable 8-b 7×7 spatial filters is described. The processor consists of an analog input buffer, 49 multipliers, and 49 8-b 20-stage local memories in a 29-mm ² chip area. Better than 99.999% charge transfer efficiency and greater than 42-dB dynamic range have been achieved by the processor, which performs one billion arithmetic operations per second and dissipates less than 1 W when clocked at 10 MHz. The device is also suited for neural networks with local connections and replicated weights. Implementation of a specific neural network, the neocognitron, based on this CCD processor has been simulated. The effect of weight quantization imposed by use of this CCD device on the performance of the neocognitron is presented