Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Noriko Ishibashi

Nobufusa Iwanishi

Kazuhiro Satoh

Masahiko Toyonaga

Keiichi Kurokawa

Masaaki Hirata

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

A method for designing a semiconductor integrated circuit is provided that is capable of a timing simulation that is approximate to an actual operation by reducing the effect of IR drop on the timing without reducing an effective area necessary for arrangement of elements or the number of pads that can be used other than power supply pads and without increasing the processing time. In a FF driving ability change procedure, a flip-flop having a delay time larger than a transition time from a state in which an IR drop occurs in a power supply voltage to a state of an ideal power supply voltage is substituted for an arbitrary flip-flop. Thus, a delay library considering IR drop may be produced previously only for the flop-flop, thus enabling a production time of the library to be reduced and improving the calculation accuracy of the delay time in the delay calculation procedure. Furthermore, the substitution of a flip-flop having a low driving ability enables the area to be reduced.

Method for designing semiconductor integrated circuit

A method for designing a semiconductor integrated circuit device for connecting between terminals of transistors formed on a silicon wafer by metal wiring. The method includes a first step of carrying out a schematic arrangement so as to minimize a distance of a wiring for connecting between the transistors or wiring capacitance based on input information on transistors; a second step of producing information on a voltage drop value based on the schematic arrangement of the transistors; and a third step of arranging the transistors based on the information on a voltage drop value.

Method and apparatus for designing semiconductor integrated circuit device based on voltage drop distribution

A semiconductor integrated circuit includes: a first register connected to the input of a first group of logic devices; a second register connected between the first and second groups of logic devices; and a third register connected to the output of the second group of logic devices. The integrated circuit is designed in the following manner. First, a shortest one of delays caused by respective signal propagation paths between the first and second registers and a shortest one of delays caused by respective signal propagation paths between the second and third registers are added together to obtain a shortest total delay. Next, if the shortest total delay is longer than a time obtained by subtracting one clock cycle time from a sum of constraint times defining respective signal propagation times between the first and second registers and between the second and third registers, then the second register is removed, thereby connecting the first and second groups of logic devices together.

Growing community of inventors

Mishima-gun, Japan

Noriko Ishibashi