Iterative Search Algorithm of Minimum Coverage for Large Size Literal Set

There is a NP-hard problem that derive the minimum coverage of multi-output logic circuit in two-level logic synthesis.When the number of output variables and the prime implicants grow up,the excessively long processing time and large memory space requirement are the major problem,which affect the possibility of coping with the problem of coverage minimization.An iterative algorithm for coverage minimization is presented based on the extract algorithm,which changes the one-time computing process into iterative searching mode of the optimum result.In contrast to the classical approaches,the proposed method can handle complex problem in reasonable time while the result is near by the optimum.At the same time,two major phases were improved:array union from single-output to multi-output and the selection of external value,which mainly affect the algorithm complexity.Experimental results show that the new algorithm superior to the others especially for decreasing the time-space complexity.