Abstract: A logic design automation system examines correspondence relationship among sublogics in intermediate gate-level logic (containing neither physical design information nor manually optimized logic design information) produced from updated functional-level logic and current gate-level logic (containing the above information) to identify corresponding sublogics and non-corresponding sublogics of the gate-level logics with reference to primary input/output signals and input/output gates. For the corresponding sublogics, the corresponding sublogics of the current gate-level logic are selected, and for the non-corresponding sublogics, the non-corresponding sublogics of the intermediate gate-level logic are selected. The selected sublogics are combined to synthesize updated gate-level logic which preserved therein the physical design information and the manually optimized logic design information for portions of the current gate-level logic which need not be modified.

Abstract: In automatic development of the higher hierarchic logic into the lower hierarchic logic in a hierarchic logic designing, identification codes are beforehand assigned to logic components of the higher hierarchic logic, and the identification codes are also assigned to the lower hierarchic logic data when developing the higher hierarchic logic into the lower hierarchic logic in order to establish correspondences between the higher and lower hierarchic logic, thereby allowing a higher-speed logic compare operation with respect to a design change on the higher or lower hierarchic logic and enabling the automatic update of the lower hierarchic logic by use of the higher hierarchic logic as the master.