A semiconductor integrated circuit manufacturing method for manufacturing a semiconductor integrated circuit using, for circuit design, a semiconductor integrated circuit designing method for automatically generating a pattern of the semiconductor integrated circuit under control of a computer, said semiconductor integrated circuit designing method comprising:
- an input step of inputting gate level logic circuit information, standard cell library information, and package information of a circuit block as a constituent of the semiconductor integrated circuit;
- a noise estimation step of estimating an amount of noise that may occur in the circuit block, using the inputted information;
- a capacitance constraint designation step of designating a capacitance constraint that is a capacitance of a bypass condenser for reducing power supply noise and substrate noise, which bypass condenser is to be incorporated in the circuit block to restrict the amount of noise within a predetermined range, on the basis of the estimated amount of noise;
- a comparison step of comparing an on-chip capacitance that is a capacitance of a bypass condenser incorporated in the circuit block, with the capacitance constraint;
- a processing ending step of ending the automatic generation of the pattern of the semiconductor integrated circuit, when the on-chip capacitance is larger than the capacitance constraint in the comparison step;
- a logic gate selection step of selecting a logic gate in the circuit block, which logic gate generates an amount of noise equal to or larger than a predetermined amount of noise, when the on-chip capacitance is equal to or smaller than the capacitance constraint in the comparison step;
- and
- a bypass condenser addition step of adding a bypass condenser to the selected logic gate;
- wherein, after the bypass condenser is added in the bypass condenser addition step, the processing returns to the comparison step, wherein the on-chip capacitance that is the capacitance of the bypass condenser incorporated in the circuit block in which the bypass condenser is added is compared with the capacitance constraint.