The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 2003
Filed:
May. 10, 2000
Advantest Corporation, Tokyo, JP;
Abstract
Apparatus of judging delay time, capable of judging whether or not delay time for delaying an input signal is equal to a desired delay, includes: a shift clock supply unit which supplies a shift clock whose phase is delayed by the desired delayed time against a phase of a reference clock; a phase comparing unit which compares a phase of the shift clock to a phase of a delay clock for which the reference clock is delayed by a delay circuit, and then outputs a comparison signal; and a judging unit which judges whether or not the delay time of the delay circuit is equal to the desired delay time. A method therefor includes: generating a shift clock which delays a phase of a reference clock by a predetermined amount based on a desired delay time; comparing a phase of the delay clock to that of the shift clock; judging whether or not the phase of the shift clock matches that of the delay clock; and repeating a step of generating the shift clock, a step of comparing the phase and a step of judging until the phase of the delay clock matches that of the shift clock.