Agilent Technologies, Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Avago Technologies General IP Pte, Ltd.

Other

Hewlett-packard Company

Jeffrey R Rearick

John G Rohrbaugh

Shad R Shepston

Peter Jacob Meier

Alvin Leng Sun Loke

Michael Joseph Gilsdorf

Richard S Rodgers

John Bratt

Cory D Groth

Charles E Moore

Guy Harlan Humphrey

David Lawrence Linam

Louise A Koss

Jacob Lee Bell

Dale Beucler

Mary Louise Nash

Manish Sharma

Xiaoyang Zhang

A method and apparatus for testing an integrated circuit interconnect comprises an IC having circuitry embedded in the IC capable of providing a pseudo time domain reflectometry test by launching a test transition onto the interconnect and capturing a reflection of the test transition.

Method and apparatus for an embedded time domain reflectometry test

An apparatus and method for compensating clock period elongation during scan testing in an integrated circuit (IC) includes operating a clock associated with the IC at a frequency (f) at which IC operation is sought to be determined, measuring the actual clock period (T) at a clock output, scan testing the IC, measuring the actual clock period (T) at the clock output, determining a delay by calculating the difference between Tand T, and compensating for the delay by increasing the clock frequency during scan test.

Apparatus and method for compensating clock period elongation during scan testing in an integrated circuit (IC)

The invention provides a method and an apparatus for enabling a user to determine whether a defective location in a memory device of an integrated circuit (IC) has been remapped to a location in a redundant memory portion of the memory device. Users are provided with the ability to observe the remapping, and preferably, to determine which locations in the memory device have been remapped. The memory device includes remapping observation logic that causes bits associated with remapping to be output from the memory device. Preferably, a computer receives the remapping bits and displays a description of any remapping on a display monitor. Therefore, not only is a user able to determine whether remapping has occurred, but also which locations in the memory device have been remapped.

Method and apparatus for enabling a user to determine whether a defective location in a memory device has been remapped to a redundant memory portion

A circuit and method for determining operating speed of a clock associated with an integrated circuit (IC), includes an IC logic element, a scan chain, and a calibration circuit including a first plurality of flip-flops and a combinational delay line. The calibration circuit operates in a functional test mode and in a scan test mode to determine a clock signal delay between the functional test mode and the scan test mode.

Circuit and method for comparing circuit performance between functional and AC scan testing in an integrated circuit (IC)

Systems and methods for reconfiguring scan chains are provided. A representative system incorporates a first scan chain of flip-flops operative in either a normal mode or a rotate mode such that, if the first scan chain is operative in the normal mode, inputs are provided to the flip-flops in sequential order with a first of the flip-flops receiving an input prior to a second of the flip-flops, and, if the first scan chain is operative in the rotate mode, inputs are provided to the flip-flops with the first of the flip-flops receiving an input subsequent to the second of the flip-flops.

Systems and methods for reconfiguring scan chains

A test system includes a circuit assembly having an IC and an external circuit. The IC includes test circuitry used to observe data indicative of target resistances in the external circuit. The test system evaluates the data to determine target resistance values. A first embodiment measures two output voltages responsive to a time varying reference voltage. The two output voltages can be used to determine resistance values in the external circuit. A second embodiment enables logic contention on the IC, controllably fixes a pull-down element on the IC, and controllably sweeps a pull-up element on the IC until the voltage at a node between the pull-down and pull-up elements and coupled to an external circuit exceeds a reference voltage.

Testing target resistances in circuit assemblies

A delay-locked loop (DLL) of an integrated circuit (IC) with testing circuitry and a method for testing a DLL. During test mode, a phase comparator of the DLL receives a test clock in place of the reference clock and determines the phase difference between the test clock and the clock fed back to the DLL from a clock buffer tree. A variable delay element of the DLL then shifts the reference clock in time by an amount that depends on that phase difference. The variable delay element can be exercised by varying the phase of the test clock with respect to the reference clock by a known phase offset to cause the variable delay element to produce a range of delays. Whether the variable delay element is functioning properly can be determined by checking whether the phase of the test clock is aligned with the phase of the feedback clock.

Delay-locked loop and a method of testing a delay-locked loop

Disclosed is a Boundary-Scan test receiver for capturing signals during board interconnect testing. The test receiver has a comparator with a first input to receive signals during board interconnect testing, and a second input to receive a reference voltage. A programmable hysteresis circuit is coupled to at least one of the comparator's inputs. The programmable hysteresis circuit may be configured to program a hysteresis voltage and/or a hysteresis delay, both of which help prevent the comparator from integrating signal noise.

Programmable hysteresis for boundary-scan testing

A scan test architecture is implemented. The scan test architecture provides a method of performing scan test of unbalanced scan chains. The scan test architecture generates a control signal (i.e., masking signal) to mask bits in an unbalanced scan chain. In one embodiment, the control signal is generated with a logic gate, a comparator, and a counter.

System and method for automatic masking of compressed scan chains with unbalanced lengths

In one embodiment of the present invention, a scan test methodology is implemented which generates a test pattern set. A linear-time analysis is then performed on the test pattern set. As a result a new test pattern set is generated. Comparisons are made between the original test pattern set and the new test pattern set to analyze any difference in faults detected by the original test pattern set and the new test pattern set. If there are any differences in faults, test pattern generation is performed using the new test pattern set and the original test pattern set is used to augment the new test pattern set.

Method for determining the impact on test coverage of scan chain parallelization by analysis of a test set for independently accessible flip-flops

An apparatus and method for compensating clock period elongation during scan testing in an integrated circuit (IC) includes operating a clock associated with the IC at a frequency (fTARGET) at which IC operation is sought to be determined, measuring the actual clock period (TCLOCK_OUT) at a clock output, scan testing the IC, measuring the actual clock period (TSCAN_CLOCK_OUT) at the clock output, determining a delay by calculating the difference between TSCAN_CLOCK_OUT and TOLOCK_OUT, and compensating for the delay by increasing the clock frequency during scan test.

Methods for testing integrated circuits (ICs) are provided. An embodiment of a method comprises: electrically interconnecting automated test equipment (ATE) with the IC; providing at least one stimulus such that the IC determines the presence of a leakage current of the first pad; and receiving information corresponding to the leakage current of the first pad. Systems also are provided.

Systems and methods for facilitating testing of pads of integrated circuits

A delay-locked loop (DLL) of an integrated circuit (IC) with testing circuitry and a method for testing a DLL. During test mode, a phase comparator of the DLL receives a test clock in place of the reference clock and determines the phase difference between the test clock and the dock fed back to the DLL from a clock buffer tree. A variable delay element of the DLL then shifts the reference clock in time by an amount that depends on that phase difference. The variable delay element can be exercised by varying the phase of the test clock with respect to the reference clock by a known phase offset to cause the variable delay element to produce a range of delays. Whether the variable delay element is functioning properly can be determined by checking whether the phase of the test clock is aligned with the phase of the feedback clock.

Integrated circuits (ICs) are provided. A representative IC includes a first pad electrically communicating with at least a portion of the IC. The first pad includes a first driver and a first receiver, with the first driver being configured to provide a first pad output signal to a component external to the IC, and the first receiver being configured to receive a first pad input signal from a component external to the IC. The first receiver also is configured to provide, to a component internal to the IC, a first receiver digital output signal in response to the first pad input signal. A first test circuit also is provided that is internal to the IC. The first test circuit is adapted to provide information corresponding to the driver tristate leakage current of the first pad. Methods, computer-readable media, systems and other ICs also are provided.

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Fort Collins, CO, United States of America

Jeffrey R Rearick