CHANGE POINT DETECTION CIRCUIT, JITTER MEASUREMENT DEVICE, AND TEST DEVICE

摘要

A change point detection circuit detects a timing of a change point where a logical value of a signal to be measured changes. The change point detection circuit includes: a multi strobe circuit for generating a logical value data string obtained by detecting logical values of signals to be measured according to strobes of different phases; a change point detection unit for detecting in which strobe the logical value changes according to the logical value data string; an edge specification storage unit for storing in advance specification concerning the change point of which edge type, i.e., the rise edge or the fall edge of the signal to be measured is to be detected; a selection unit for selecting a change point corresponding to the edge type stored in the edge specification storage unit among the change points detected by the change point detection unit; and a strobe position storage unit for storing to which strobe the change point selected by the selection unit corresponds.