Method of integrated circuit design by selection of noise tolerant gates

Abstract

A method of integrated circuit design using the selective replacement of increasingly noise tolerant cells is disclosed. The method involves compiling a library comprising a plurality of design element cells, sorting the library into groups of functionally-equivalent cells, and ordering the cells in each group from one extreme to the other extreme value of a featured parameter for which the integrated circuit is to be tested. Each one of the cells in the library have a known value of another parameter so that the substitution of a library cell for an original cell or another library cell does not affect the overall integrated circuit value for that known parameter. A substitution can thus be made with the knowledge that additional problems involving the known parameter are not being created. If a test of the integrated circuit discovers a problem in a particular cell's performance with regard to the featured parameter the appropriate library group is accessed and the failing cell is replaced with the first unused cell in the group. The process is repeated until the integrated circuit passes a performance test.