Design of multiple-valued programmable logic array with unary function generators

This paper describes the benefit of utilizing the unary function generators in a multiple-valued Programmable Logic Array (PLA). We will clarify the m ost suitable PLA structure in terms of the array size. The multiple-valued PLA considered here has a structure with two types of function generators ( literal and unary function generators), a first-level array and a second-le vel array. On investigating the effectiveness to reduce the array size, we can pick up four form PLAs: MAX-of-TPRODUCT form, MIN-of-TSUM-form, TSUM-of -TPRODUCT form and TPRODUCT-of-TSUM form PLAs among possible eight form PLA s constructing from the MAX, MIN, TSUM and TPRODUCT operators. The upper bo und of the array sizes with v UGs is derived as ([log(2) p]-p upsilon + p(n - upsilon) + 1) p(n-1) to realize any n-variable p-valued function. Next, experiments to derive the smallest array sizes are done for 10000 randomly generated functions and 21 arithmetic functions. These results conclude tha t MAX-of-TPRODUCT form PLA is the most useful in reducing the array size am ong the four form PLAs.