| 摘要 |
A designing apparatus includes an initial estimating portion, a general power supply noise analyzing portion, a layout designing portion, a detail estimating portion, a detail power supply noise analyzing portion, and a layout adjusting portion. The initial estimating portion estimates general values of an entire consumed current and an entire on-chip capacitance. Based on the estimated general values, the general power supply noise analyzing portion creates a lumped constant circuit model so as to conduct a power supply noise analysis, for computing a current-capacitance ratio. Based on the current-capacitance ratio, the layout designing portion performs placement of cells for each of predetermined regions obtained by dividing a placement region. The detail estimating portion creates a lumped constant circuit model for each of the predetermined regions so as to estimate detail values of the consumed current and the on-chip capacitance for each of the predetermined regions. Based on the detail values, the detail power supply noise analyzing portion conducts a detail power supply noise analysis. Based on a result of the detail power supply noise analysis, the layout adjusting portion performs adjustment of the placement of the cells. |
