Method and apparatus for designing semiconductor integrated device using noise current and impedance characteristics of input/output buffers between power supply lines

摘要

In a method for designing a semiconductor integrated device, there are prepared a first power supply cell having a first decoupling capacitance and a second power supply cell having a second decoupling capacitance larger than the first decoupling capacitance. One of the first and second power supply cells is arranged in each of power supply cell areas of an input/output circuit area of the semiconductor integrated device in accordance with frequency-to-impedance characteristics at a predetermined point of input/output buffers of the input/output circuit area between first and second power supply lines thereof and frequency-to-noise current characteristics of the input/output buffers of the input/output circuit area between the first and second power supply lines.