Functional Memory and Its Microprogramming Implications

Functional memory (FM) is a general-purpose systems technology and has been proposed as a solution to the problems of large-scale integration. It is based on an associative array, composed of writable storage cells capable of holding three states; 0, 1, and DON'T CARE. The functional memory module can be used either as a local store, control store, associative store, or logic block. In its use as a logic block, logic is performed by associative table lookup, using the DON'T CARE state to give significant compression of tables over conventional two-state arrays (typically n to n2 words for functional memory instead of 20 words for conventional two-state arrays). The basic properties of functional memory are described in [1].