Patent ID: 7840858

Claim:
A detection apparatus comprising: a multi-strobe generating section that generates a plurality of strobe signals with phases different from one another; a plurality of acquiring sections each of which acquires a signal value of a signal under measurement at a timing of a corresponding strobe signal; a plurality of changing point detecting sections each of which receives the signal value of the signal under measurement from one of the acquiring sections at the timing of the corresponding strobe signal and the signal value of the signal under measurement from another of the acquiring sections at the timing of an adjacent strobe signal and detects a changing point of the signal under measurement between the two adjacent strobe signals when the two received signal values are different from one another; a mask setting section that enables at least one of the plurality of changing point detecting sections and disables at least one of the plurality of changing point detection sections, the output of the disabled changing point detection sections being masked; a changing timing output section that outputs a changing timing of the signal under measurement based on an output of the enabled changing point detecting sections; a reference signal setting section that sets which signal value among a plurality of signal values acquired by the plurality of acquiring sections is a reference signal value indicative of a value before or after the signal under measurement changes; and a reference signal selecting section that selects the reference signal value among the plurality of signal values and outputs the selected reference signal value, wherein the changing timing output section detects a glitch in response to two or more changing point detecting sections that are enabled by the mask setting section detecting two or more changing points, and the mask setting section narrows a range of the enabled changing point detecting sections in response to the changing timing output section detecting the glitch.