Fujitsu Corporation

Shuji Yoshida

Kenji Yoshida

Daisuke Miura

Masayuki Okamoto

Toshio Arakawa

Mitsuaki Nagasaka

Hiroyuki Honda

Yoshihiko Koike

Tetsuya Yoshida

A semiconductor device includes an external oscillation circuit connected to an external resonator, a self-exciting oscillation circuit, and an oscillation clock monitoring circuit, the oscillation clock monitoring circuit monitors an oscillation state of the external resonator using a clock signal generated by the self-exciting oscillation circuit, and when judged that the oscillation state has been stabilized, the terminating signal of the waiting time for stabilization of oscillation is outputted to terminate the waiting time for stabilization of oscillation of a microcomputer forcedly.

Semiconductor device including an external oscillation circuit

In a layout method for an LSI having a plurality of cells, automated arrangement of cells is performed on the basis of a netlist, which has cells and connection data therefor, and timing conditions, and, once a timing optimization processing is performed so that a plurality of cells are arranged on a chip, global wiring processing is implemented and the wiring congestion rate is analyzed. In addition, in small regions where a wiring congestion rate is so high that detailed wiring processing is judged to be difficult, cell rearrangement processing is implemented. Next, detailed wiring processing is performed with respect to the cells which have been rearranged. The rearrangement of cells is performed only in small regions with a high congestion rate, with the result that the overall cell arrangement in which timing is optimized is not changed markedly, whereby it is possible to reduce the probability of wiring being impossible in the course of the detailed wiring processing.

LSI layout method and apparatus for cell arrangement in which timing is prioritized

Each binary carry logic circuit of half adder circuits other than that for the least significant digit comprises a transfer gate turned on when an input bit A is active and receiving a carry-in bit *C at its data input, and a transistor , turned on when the input bit A is inactive, connected between a power supply potential VDD and the data output of the transfer gate a signal on which is a carry-out bit *C . Transfer gates to of binary carry logic circuits other than that for the least significant digit are connected in chain, and are simultaneously on/off controlled by input bits A to A , letting the carry-in bit *C from the least significant digit propagate through the transfer gate chain at a high speed.

Logic circuit for fast carry/borrow

Disclosed is a method for automatic wiring design between block circuits of an integrated circuit, which performs an automatic connection between an inter-block wire disposed between a first circuit block and a second circuit block, and terminals formed along sides of the first and second blocks, the sides facing each other. The method comprises the steps of (S ) sorting the terminals according to the width thereof; and (S S ) selecting a terminal from the terminals in descending order of the width, and connecting between the selected terminal and an inter-block wire belonging to a same net as the terminal. In another embodiment, the method comprises the steps of (a) sorting the terminals, connected to a power supply wire, according to the value of electric current passing through the terminals; and (b) selecting a terminal from the terminals in descending order of the value of electric current and connecting between the selected terminal and an inter-block wire belonging to a same net as the selected terminal.

Method and apparatus for automatic wiring design between block circuits of integrated circuit

A semiconductor device that prevents malfunction in an external circuit by preventing an indefinite signal from being output at the time of power being applied. A processing circuit is supplied with an internal power supply voltage from an internal power supply voltage generating circuit and performs a predetermined process. An output circuit outputs the result of processing by the processing circuit. When the supply of an external power supply voltage is begun, a control circuit exercises control so that output from the output circuit will be kept in a predetermined state. A supply circuit supplies an external power supply voltage to the control circuit.

Growing community of inventors

Kawasaki, Japan

Shuji Yoshida