Abstract: 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.

Abstract: 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 TCLOCK—OUT, and compensating for the delay by increasing the clock frequency during scan test.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A preferred integrated circuit for facilitating receiver trip level testing functionality includes a first pad which incorporates a first driver and a first receiver. The first driver is configured to provide a first pad output signal to a component external to the IC. The first receiver is configured to receive a first pad input signal from a component external to the IC, and to provide a first receiver digital output signal to a component internal to the IC in response to the first pad input signal. Additionally, a first test circuit is provided that is arranged internal to the IC, with the first test circuit being adapted to provide information corresponding to at least one receiver trip-level characteristic of the first receiver of the first pad. Systems, methods and computer readable media also are provided.

Abstract: Methods for testing integrated circuits (ICs) are provided. An exemplary method, in which the IC has a first pad configured as a signal interface for components external to the IC, the first pad having a receiver configured to receive an input signal from a component external to the IC, comprises: electrically interconnecting automated test equipment (ATE) with the IC; providing at least one stimulus to the IC such that the IC measures a receiver termination characteristic of the first pad; and receiving information corresponding to the receiver termination characteristic of the first pad. Systems and integrated circuits also are provided.

Abstract: A scan test methodology is presented. 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.

Abstract: Integrated circuits (ICs) are provided. A representative IC includes a first pad that incorporates 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. 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 strength of the first pad. Systems, methods, computer-readable media and other ICs also are provided.