Systems and methods for testing and diagnosing delay faults and for parametric testing in digital circuits
First Claim
1. A method of performing delay-fault testing on an integrated circuit, comprising:
- providing an integrated circuit comprising combinational logic that includes a plurality of data paths outputting corresponding respective data bits to a plurality of memory elements;
clocking the combinational logic and ones of the plurality of memory elements with a first clock signal having a period;
simultaneously with said clocking with the first clock signal, providing a particular memory element of the plurality of memory elements with a shorter launch-capture cycle that is shorter than the period of the first clock signal, the shorter launch-capture cycle being implemented using two separate, but simultaneous, delayed clocks; and
determining whether a delay fault occurred on the particular data path of the plurality of data paths corresponding to the particular memory element provided with the shorter launch-capture cycle as a function of the shorter launch-capture cycle.
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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.
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Citations
10 Claims
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1. A method of performing delay-fault testing on an integrated circuit, comprising:
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providing an integrated circuit comprising combinational logic that includes a plurality of data paths outputting corresponding respective data bits to a plurality of memory elements; clocking the combinational logic and ones of the plurality of memory elements with a first clock signal having a period; simultaneously with said clocking with the first clock signal, providing a particular memory element of the plurality of memory elements with a shorter launch-capture cycle that is shorter than the period of the first clock signal, the shorter launch-capture cycle being implemented using two separate, but simultaneous, delayed clocks; and determining whether a delay fault occurred on the particular data path of the plurality of data paths corresponding to the particular memory element provided with the shorter launch-capture cycle as a function of the shorter launch-capture cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of implementing delay-fault testing for an integrated circuit, comprising:
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during a design phase of designing an integrated circuit, identifying small delay paths from a plurality of data paths; providing ones of the plurality of data paths with a corresponding respective plurality of first scannable memory elements; providing the integrated circuit with additional, second scannable memory elements to the outputs of the small delay paths; providing the integrated circuit with further, third scannable memory elements in communication with corresponding respective ones of the second scannable memory elements, the third scannable memory elements for capturing delay-fault signals; providing the integrated circuit with a functional clock network for providing a first clock signal to the plurality of data paths and the plurality of first scannable memory elements; providing the integrated circuit with a time-base generator for providing a second clock signal to the second scannable memory elements, the second clock signal having a delay relative to the first clock signal; programming the time-base generator so that the delay is an optimal value; scanning appropriate data values for transition fault testing into the plurality of first scannable memory elements and the second scannable memory elements; performing the transition fault testing using the first and second clock signals simultaneously with one another; and subsequent to said performing of the transition fault testing, scanning test values out of at least the third scannable memory elements. - View Dependent Claims (10)
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Specification