| 摘要 |
PURPOSE:To keep the value of a voltage drop within a tolerance by a method wherein, after a standard cell has been formed, the line width of a wiring part for the power source is decided so that the arrangement of formed cell arrays can be maintained. CONSTITUTION:The height Y of a standard cell is kept constant while the width X is changed according to a circuit. A certain value of wiring parts 1, 2 for the power source is input by designating the width W as a default value. Cell arrays 4-6 and mutual wiring parts 7-10 constitute a block and are connected to wiring parts 11, 12 for the power source for the block. The amount of power consumed is measured for each block. If blocks A-F are arranged and the interconnections to the power source is shown by an arrow, each block shows a cumulative drop S which is composed of a voltage drop V caused by its own passing current i and a voltage drop V of a block connected to a higher position. For example, if a drop of a block F exceeds a tolerance value of 150 mV and shows 200 mV, the tolerance can be maintained in such a way that each eidth W for wiring parts D, E and F is multiplied by 200/150. If the most suitable value for the width of the wiring part is obtained precisely, it is possible to prevent the occurrence of a reject. |
