Methods of Parametric Testing in Digital Circuits
First Claim
1. A method of measuring a parameter of a signal under test in an integrated circuit, comprising:
- providing an integrated circuit that generates a periodic signal having a frequency;
generating from within the integrated circuit a time-base signal having the frequency of the periodic signal and a variable delay relative to the periodic signal;
sampling, with a one-bit sampler over a number N of cycles of the time-base signal, the periodic signal in response to the time-base signal a plurality of times each having a differing value of the variable delay; and
for each of the plurality of times, counting over the N cycles the number of sampled occurrences of a particular bit value captured by the one-bit sampler.
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Accused Products
Abstract
Delay-fault testing and parametric analysis systems and methods utilizing one or more variable delay time-base generators. In embodiments of the delay-fault testing systems, short-delay logic paths are provided with additional scan-chain memory elements and logic that, in conjunction with the one or more variable-delay time-base generators, provides the effect of over-clocking without the need to over-clock. Related methods provide such effective over-clocking. In embodiments of parametric analysis systems, test point sampling elements and analysis circuitry are clocked as a function of the output of the one or more variable-delay time-base generators to provide various parametric analysis functionality. Related methods address this functionality.
90 Citations
10 Claims
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1. A method of measuring a parameter of a signal under test in an integrated circuit, comprising:
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providing an integrated circuit that generates a periodic signal having a frequency; generating from within the integrated circuit a time-base signal having the frequency of the periodic signal and a variable delay relative to the periodic signal; sampling, with a one-bit sampler over a number N of cycles of the time-base signal, the periodic signal in response to the time-base signal a plurality of times each having a differing value of the variable delay; and for each of the plurality of times, counting over the N cycles the number of sampled occurrences of a particular bit value captured by the one-bit sampler. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification