A Novel Essential Prime Implicant Identification Method for Exact Direct Cover Logic Minimization

Most of the direct-cover Boolean minimization techniques use a four step cyclic algorithm. First, the algorithm chooses an On-minterm; second, it generates the set of prime implicants that covers the chosen minterm; third, it identifies the essential prime implicant; and fourth, it performs a covering operation. In this study, we focus on the third step and propose a new essential prime implicant identification method. In this method, when the identification of the essential prime implicant is impossible, we postpone dealing with current On-minterm and save a status word for it. Eventually, we retrieve the status words whenever a new essential prime implicant is identified. We compared the proposed minimization method with ESPRESSO-EXACT. The results show that our method obtains exact results faster than other ones.