Delay calculating method in semiconductor integrated circuit

Abstract

An input pin capacitance of a cell is obtained in advance in a function expression, and a delay is calculated in such manner that the input pin capacitance is calculated in functions of an input slew and a drive load capacitance in each instance. In a cell characterizing process, a total volume of a current running into an input terminal before a voltage value of the input terminal reaches a reference voltage is obtained so that a value approximate to a real input pin capacitance can be obtained.

1 . A delay calculating method in a semiconductor integrated circuit comprising:
 a function setting step in which a function for calculating an input pin capacitance of an instance constituting a cell constituting the semiconductor integrated circuit in a characterizing process of the cell and expressing a predetermined parameter in the form of an argument, is set per cell;   a parameter calculating step in which a delay library of each cell, a wire capacitance and an resistance of each cell, an initial value of the input pin capacitance of the cell and a cell connection information of the cell are inputted so as to calculate the parameter in each instance;   an input pin capacitance calculating step in which the argument including the parameter obtained in the parameter calculating step is assigned to the function set in the function setting step so as to calculate the input pin capacitance in each instance; and   a delay calculating step in which a delay is calculated by means of the input pin capacitance of the instance obtained in the input pin capacitance calculating step, wherein the calculation of the parameter in each instance is repeated whenever necessary.   
     
     
         2 - 17 . (canceled)