Programmable Array Realizations of Synchronous Sequential Machines

Cellular-array realizations of switching functions have been studied in order to take advantage of the many design possibilities offered by large-scale integration technology. This paper introduces a class of programmable cellular arrays that can be employed to realize arbitrary synchronous sequential machines. State assignments based upon k-out-of-m codes are employed to give rise to machine excitation and output equations in a consistent functional form suitable for implementation via a cellular structure. The proposed arrays are programmable, which makes possible the capability of re-configuring an array to realize different machines by electronically altering the function implemented by each cell of the array. A synthesis algorithm is presented that will allow the designer to program the array without explicitly deriving excitation and output functions. The synthesis technique is applicable to both Mealy and Moore machines with any number of inputs, outputs, and internal states, and utilizing either delay or trigger flip-flops.