Hitachi, Ltd.

Nobuo Motoki

Kenichi Shinbo

Fujio Oonishi

Masashi Fukuzaki

Ritsuro Orihashi

Ritsurou Orihashi

A pulse generation circuit including a pulse formation circuit for generating normal and dummy pulses according to second delay value data, a data calculation circuit for calculating first delay value data at a timing at which the pulses are generated from the pulse formation circuit according to pattern data having information for determining whether to generate pulses from the pulse formation circuit, a dummy pulse control circuit for controlling generation of a dummy pulse in a no-pulse-generation cycle from the pulse formation circuit according to the second delay value data obtained by detecting the no-pulse-generation cycle from the first delay value data, and a logical gate circuit for eliminating the dummy pulses generated from the pulse formation circuit.

Pulse generation circuit and semiconductor tester that uses the pulse generation circuit

In an odd side storage circuit, logical values of a decision subject signal HCMP are stored in first and second FFs respectively at decision edges LH and HL generated from odd-numbered edges of a decision edge EH. Logical values of a delayed decision subject signal HCMP&prime; are stored in third and fourth FFs. According to a selection signal generated by a selection signal generation circuit based on outputs of the third and fourth FFs, a first selector selects an output of the first or second FF. An even side storage circuit operates similarly at even-numbered edges. A second selector selects the odd and even side storage circuits alternately. The FFs in the odd and even side storage circuits are reset by a decision edge LH&prime; of the even side and the decision edge HL of the odd side, respectively.

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Isezaki, Japan

Nobuo Motoki