VLSI Implementation of a Neural Network Memory With Several Hundreds of Neurons.

We designed an Electronic Neural Network (ENN) memory with 25beta neurons on a single chip using a combination of analog and digital VLSI technology plus a custom microfabrication process. Amplifiers with inverting and noninverting outputs are used for the neurons to make inhibitory and excitatory connections. The connections between the individual neurons are provided by amorphous-silicon resistors which are placed on the CMOS chip in the last fabrication step. This technique allows a very dense packing of the neurons. Electron-beam direct-writing is used to pattern the resistors making it easy to change the information stored in the network from one chip to the next.