Prime Indicants: A Synthesis Method for Indicating Combinational Logic Blocks

Self-timed circuits present an attractive solution to the problem of process variation. However, implementing self-timed combinational logic is complex and expensive. This paper presents a novel method for synthesising indicating implementations of arbitrary encoded function blocks. The synthesis method reduces the cost of the implementations by distributing indication between the individual outputs of a function block. Covers are constructed by determining the minimal cost set of Prime Indicants which are required to indicate all of the input transitions of the function block. The results of the procedure are demonstrated on a wide range of combinational logic blocks and show a reduction in literal count of between 38-99%.