Patent ID: 8166443

Claim:
A method of shield line placement for a semiconductor integrated circuit, comprising: accepting an input of a placement instruction of a signal line and storing first wiring data including coordinate information of the signal line and a first identifier in a memory; creating second wiring data of a shield line including coordinate information of the shield line and a second identifier by following a wiring rule that defines a mode of placement of the shield line in accordance with the mode of placement of the signal line, and storing the second wiring data in the memory; creating association information for associating the first and second identifiers; changing the wiring rule; specifying a pair of the first wiring data of the signal line inputted before the changing of the wiring rule and the second wiring data of the shield line associated with the signal line inputted before the changing of the wiring rule, by the association information, using a computer; and changing the second wiring data of the shield line of the pair specified, in accordance with the first wiring data of the signal line of the pair, by following the wiring rule after being changed.