Patent ID: 7856578
Filing Date: 2010-12-21
Classification: G01R

Abstract:
1. A method for testing timing of a data signal, comprising: applying a first strobe initiator pulse to a first plurality of delay elements to generate a plurality of delayed copies of the first strobe initiator pulse; applying a data signal to an input of each of a first plurality of latches; applying each of the plurality of delayed copies of the first strobe initiator pulse as a latch-clock signal to a corresponding latch of the first plurality of latches wherein a plurality of samples of the data signal is thereby acquired; encoding the plurality of samples of the data signal to form a first digital word which identifies a time and a polarity of a state change in the data signal; storing the first digital word in random access memory; applying a second strobe initiator pulse to a second plurality of delay elements to generate a plurality of delayed copies of the second strobe initiator pulse; applying a clock signal to an input of each of a second plurality of latches; applying each of the plurality of delayed copies of the second strobe initiator pulse as a latch-clock signal to a corresponding latch of the second plurality of latches wherein a plurality of samples of the clock signal is thereby acquired; encoding the plurality of samples of the clock signal to form a second digital word which identifies a time and a polarity of a state change in the clock signal; and determining a delay between the state change in the data signal and the state change in the clock signal by comparing the second digital word with the first digital word.