Patent ID: 6574579
Filing Date: 2003-06-03
Classification: G01R

Abstract:
A waveform generating apparatus comprising:delay data selecting means selecting, out of a plurality of delay data, at least one delay data for generating at least one set pulse and at least one delay data for generating at least one reset pulse in accordance with test logical data and waveform mode information externally supplied thereto; skew data storage means for set pulse and for reset pulse, said skew data storage means storing therein skew adjusting delay data for a propagation path of a delay data for set pulse and for a propagation path of a delay data for reset pulse, respectively; operation means for set pulse and for reset pulse, said operation means performing an operation of the set pulse delay data, the skew adjusting delay data for set pulse and a fraction data in each test cycle externally supplied thereto and an operation of the reset pulse delay data, the skew adjusting delay data for reset pulse and a fraction data in each test cycle externally supplied thereto, respectively, and outputting an integer delay data and a fraction delay data for set pulse from the result of the operation and an integer delay data and a fraction delay data for reset pulse from the result of the operation, respectively; delay means for set pulse and for reset pulse, said delay means outputting at least one set pulse generating effective flag for causing a timing of a test period to delay by a delay time corresponding to the integer delay data and at least one reset pulse generating effective flag for causing a timing of a test period to delay by a delay time corresponding to the integer delay data, respectively, as well as outputting fraction delay data related to these set pulse generating effective flag and reset pulse generating effective flag, respectively; variable delay means for set pulse and for reset pulse, to which the set pulse generating effective flag and the reset pulse generating effective flag are inputted respectively, said variable delay means delaying the effective flags on the basis of the related fraction delay data, respectively; and waveform outputting means outputting a waveform which is set by a set pulse supplied from said set pulse variable delay means and reset by a reset pulse supplied from said reset pulse variable delay means, for each test period.