Method and apparatus for revising wiring of a circuit to prevent electro-migration

A wiring designing method for electrically connecting a plurality of functional blocks on a semiconductor integrated circuit is disclosed, that comprises the steps of (a) obtaining a wiring branch point among the plurality of functional blocks, (b) obtaining a current density of the obtained wiring branch point, (c) determining whether or not the obtained current density exceeds a predetermined limit value, and (d) performing a process for decreasing a current density of a predetermined wiring portion that ends at the wiring branch portion whose current density exceeds the limit value corresponding to the determined result at the determining step (c).