| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems wherein the characteristic of a special eye pattern cannot be measured, such as an eye pattern having a large noise, an eye pattern having many eyes, or an eye pattern having a cross point deviated extremely upward or downward, in an eye pattern measuring method for evaluating the quality of a signal by using the eye pattern formed by overwriting a series of signals. SOLUTION: Two peaks are extracted from a time direction histogram in a prescribed range of the eye pattern, and a domain taking the maximum value is divided and a histogram in the voltage direction of the domain is determined relative to each peak, and each point where a dispersion value of the histogram becomes minimum is named as the cross points Tcrossing 1, Tcrossing 2, and the mean value thereof is named as the cross point Vcrossing of a voltage axis. A voltage direction histogram in a prescribed range between Tcrossing 1 and Tcrossing 2 is determined, and a mean value on the upper side is named as Vtop, and a mean value on the lower side is named as Vbase. Hereby, the characteristic can be measured accurately, even in the case of an eye pattern having a special shape. COPYRIGHT: (C)2007,JPO&INPIT
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