An associative memory with neural architecture and its VLSI implementation

Two VLSI special-purpose hardware implementations of an associative memory model are described: a pure digital and a mixed analog/digital architecture. Both architectures can be easily extended to large scale memories with several million storage elements. The advantages and disadvantages of both architectures are pointed out. The memory concept is based on a simple matrix structure with n×m binary elements, the connections, and on distributed storage of information like artificial neural networks. There is no asynchronous feedback and the inputs and outputs are binary, too. Though the system concept is very simple, it has an asymptotic storage capacity of 0.69.m.n bits and the number of patterns that can be stored with low error probability is much larger than the number of columns (artificial neurons). The important aspect for applications is that the input and output patterns have to be sparsely coded