In view of the problems of the published methods of the ISPFRM functions optimization which couldn't deal with large functions

a novel method for large ISPFRM function optimization was proposed which consists of the representation of product term in integer form

the polarity conversion method using the binary interpolation

and the circuit area optimization of ISFPRM using the bit-wise operation and the genetic algorithm.The proposed algorithm could deal with those functions with large inputs effectively

and has been implemented in C and tested under MCNC benchmarks.The experimental results show that it can deal with the large function with 199 inputs

and the speed of the algorithm is not sensitive to the functions' polarity.After the introduction of DC terms

the circuit area is further optimized.