Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masaaki Hirata

Nobufusa Iwanishi

Kazuhiro Sato

Kenji Shimazaki

Takahiro Ichinomiya

Ryuichi Yamaguchi

Shouzou Hirano

Noriko Ishibashi

Naoki Amekawa

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.

Delay calculating method in semiconductor integrated circuit

There are contained the step of forming voltage waveform information by calculating a voltage waveform of each instance of a semiconductor integrated circuit at a power-supply terminal based on circuit information and analyzing the voltage waveform of each instance, the step of forming voltage abstraction information by abstracting the voltage waveform information, and the step of calculating a delay value of the instance based on the voltage abstraction information.

Operation analyzing method for semiconductor integrated circuit device, analyzing system used in the same, and optimization design method using the same

A method of accurately estimating a time delay caused by a target cell where a target supply voltage is applied to the cell. Time delays, caused by a representative cell, are represented as a function of supply voltages applied to the cell, thereby deriving an approximation function k . An interpolation function k is derived from the approximation function k by reference to two points P and P . P indicates a time delay T caused by the target cell where a supply voltage V is applied thereto, while P indicates a time delay T caused by the target cell where a different supply voltage V is applied thereto. Thus, the interpolation function k represents the time delays caused by the target cell as a function of supply voltages. And by using this interpolation function k , a time delay caused by the target cell at the target supply voltage can be estimated accurately.

Method of estimating time delay

Growing community of inventors

Osaka, Japan

Masaaki Hirata