A sequence of K voltage samples of a transmitted data signal is generated by sampling, digitizing, and storing voltage samples of the data signal with an imbedded sample clock on an IC having an unknown period TS. The K voltage samples are plotted against a time base of K sequential times TB[K] normalized so all samples fall within one cycle of the data clock used to generate the data signal or a unit time of 1. The time base is generated by estimating the sample clock period TSE to be some multiple of 1/P where P is greater than K. Eye diagrams are analyzed for time jitter wherein only the minimum value of jitter is saved. TSE is incremented by 1/P until TS is greater than one half the data clock period. The eye diagram at the TSE with the minimum time jitter is used to analyze the data channels.