Abstract: A system and method for improving the yield rate of a multiprocessor semiconductor chip that includes primary processor cores and one or more redundant processor cores. A first tester conducts a first test on one or more processor cores, and encodes results of the first test in an on-chip non-volatile memory. A second tester conducts a second test on the processor cores, and encodes results of the second test in an external non-volatile storage device. An override bit of a multiplexer is set if a processor core fails the second test. In response to the override bit, the multiplexer selects a physical-to-logical mapping of processor IDs according to one of: the encoded results in the memory device or the encoded results in the external storage device. On-chip logic configures the processor cores according to the selected physical-to-logical mapping.

Abstract: A method of locating faulty logic on a semiconductor chip is disclosed. The method may include determining failure rates for the semiconductor chip, which contain one or more logic elements. The method also may include determining a masking pattern using failure rates. The masking pattern may mask less than all of the logic elements using a determination method. The method may also include applying a test vector to a selected logic element, wherein the result from a test vector is compared to a reference.

Abstract: A method for scanning a partially functional chip. The method may include applying a failed core map to the partially functional chip, bypassing at least one failed core scan chain, based on contents of the failed core map. The method may also include performing comparisons of scan status information to the failed core map and inhibiting movement of scan data of at least one failed core, based on results of the comparisons.

Abstract: Systems and methods to test processor cores of a multi-core processor microchip are provided. Comparison circuitry may be configured to compare data output from processor cores of a microchip. An encoding module may be configured to encode received data by initially assigning binary bit values to the processor cores. Based on at least one of a number of the processor cores and a first binary bit value, a first additional binary bit may be added to the first binary bit value. The first binary bit value may be assigned to a first processor core of the plurality of processor cores.

Abstract: A method of locating faulty logic on a semiconductor chip is disclosed. The method may include determining failure rates for the semiconductor chip, which contain one or more logic elements. The method also may include determining a masking pattern using failure rates. The masking pattern may mask less than all of the logic elements using a determination method. The method may also include applying a test vector to a selected logic element, wherein the result from a test vector is compared to a reference.

Abstract: A method and circuit for implementing enhanced Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. A plurality of pseudo random pattern generators (PRPGs) is provided, each PRPG comprising one or more linear feedback shift registers (LFSRs). Each respective PRPG includes an XOR feedback input selectively receiving a feedback from another PRPG and predefined inputs of the respective PRPG. A respective XOR spreading function is coupled to a plurality of outputs of each PRPG with predefined XOR spreading functions applying test pseudo random pattern inputs to LBIST channels for LBIST diagnostics.

Abstract: A method and structure tests a system on a chip (SoC) or other integrated circuit having multiple cores for chip characterization to produce a partial good status. A Self Evaluation Engine (SEE) on each core creates a quality metric or partial good value for the core. The SEE executes one or more tests to create a characterization signature for the core. The SEE then compares the characterization signature of a core with a characterization signature of neighboring cores to determine the partial good value for the core. The SEE may output a result to create a full characterization map for detailed diagnostics or a partial good map with values for all cores to produce a partial good status for the entire SoC.

Abstract: A method and structure tests a system on a chip (SoC) or other integrated circuit having multiple cores for chip characterization to produce a partial good status. A Self Evaluation Engine (SEE) on each core creates a quality metric or partial good value for the core. The SEE executes one or more tests to create a characterization signature for the core. The SEE then compares the characterization signature of a core with a characterization signature of neighboring cores to determine the partial good value for the core. The SEE may output a result to create a full characterization map for detailed diagnostics or a partial good map with values for all cores to produce a partial good status for the entire SoC.

Abstract: An apparatus and method is provided for switching input pins to scan channels to increase test coverage. In one embodiment, a scan system connects a small number of input pins to several scan channels so that the input pins may be selectively switched. The input pins may transmit independent test vectors to test a large number of test areas on a semiconductor chip. The scan system may include a switching device such as a multiplexer (MUX).

Abstract: A method of locating faulty logic on a semiconductor chip is disclosed. The method may include determining failure rates for the semiconductor chip, which contain one or more logic elements. The method also may include determining a masking pattern using failure rates. The masking pattern may mask less than all of the logic elements using a determination method. The method may also include applying a test vector to a selected logic element, wherein the result from a test vector is compared to a reference.

Abstract: A method and circuits for implementing aperture function calibration for Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. The aperture function calibration uses aperture calibration data, and an LBIST calibration channel having a predefined number of scan inversions between the aperture calibration data and a multiple input signature register (MISR). LBIST is run selecting the LBIST calibration channel and masking other LBIST channels to the MISR. A change in the MISR value, for example, from zero to a non-zero value, is identified and an aperture adjustment is calculated and used to identify any needed adjustment of aperture edges.

Abstract: In a test data access system, a shift register is coupled the test data in pin. A first multiplexer is in data communication with the TDI pin and is configured to receive data from the TDI pin and to transmit data to each of the instruments. The first multiplexer is also configured to receive data from a data recirculation bit and to transmit data from the TDI pin to a plurality of instruments when the recirculation bit has a first value and to transmit data to the plurality of instruments from a recirculation line when the recirculation bit has a second value, different from the first value. A second multiplexer is configured to receive data from each of the plurality of instruments and is configured to transmit data from a selected one of the plurality of instruments, selected based on a value of data in the shift register. A first AND gate is configured to generate a gates clock to the shift register. A second AND gate is responsive to the first AND gate, configured to lock the shift register.

Abstract: A method and circuit for implementing enhanced Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. A plurality of pseudo random pattern generators (PRPGs) is provided, each PRPG comprising one or more linear feedback shift registers (LFSRs). Each respective PRPG includes an XOR feedback input selectively receiving a feedback from another PRPG and predefined inputs of the respective PRPG. A respective XOR spreading function is coupled to a plurality of outputs of each PRPG with predefined XOR spreading functions applying test pseudo random pattern inputs to LBIST channels for LBIST diagnostics.

Abstract: A method and circuits for implementing aperture function calibration for Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. The aperture function calibration uses aperture calibration data, and an LBIST calibration channel having a predefined number of scan inversions between the aperture calibration data and a multiple input signature register (MISR). LBIST is run selecting the LBIST calibration channel and masking other LBIST channels to the MISR. A change in the MISR value, for example, from zero to a non-zero value, is identified and an aperture adjustment is calculated and used to identify any needed adjustment of aperture edges.

Abstract: A system and method for improving the yield rate of a multiprocessor semiconductor chip that includes primary processor cores and one or more redundant processor cores. A first tester conducts a first test on one or more processor cores, and encodes results of the first test in an on-chip non-volatile memory. A second tester conducts a second test on the processor cores, and encodes results of the second test in an external non-volatile storage device. An override bit of a multiplexer is set if a processor core fails the second test. In response to the override bit, the multiplexer selects a physical-to-logical mapping of processor IDs according to one of: the encoded results in the memory device or the encoded results in the external storage device. On-chip logic configures the processor cores according to the selected physical-to-logical mapping.

Abstract: For disabling a first function in an information handling system, a dynamic signal is disabled. The first function is inoperable in response to the dynamic signal being disabled. At least a second function in the information handling system is operable irrespective of whether the dynamic signal is disabled.

Abstract: In a test data access system, a shift register is coupled the test data in pin. A first multiplexer is in data communication with the TDI pin and is configured to receive data from the TDI pin and to transmit data to each of the instruments. The first multiplexer is also configured to receive data from a data recirculation bit and to transmit data from the TDI pin to a plurality of instruments when the recirculation bit has a first value and to transmit data to the plurality of instruments from a recirculation line when the recirculation bit has a second value, different from the first value. A second multiplexer is configured to receive data from each of the plurality of instruments and is configured to transmit data from a selected one of the plurality of instruments, selected based on a value of data in the shift register. A first AND gate is configured to generate a gates clock to the shift register. A second AND gate is responsive to the first AND gate, configured to lock the shift register.

Abstract: For disabling a first function in an information handling system, a dynamic signal is disabled. The first function is inoperable in response to the dynamic signal being disabled. At least a second function in the information handling system is operable irrespective of whether the dynamic signal is disabled.

Abstract: In a method of generating clock signals for a level-sensitive scan design latch, at least one test input signal is transmitted to a plurality of splitter leaves. Once the test input signal is stabilized at each of the splitter leaves, generating a shaped oscillator clock signal having a predetermined pattern of pulses from a central root is generated. At the plurality of splitter leaves, the test input signal is logically combined with the shaped oscillator clock signal, thereby generating a first latch clock signal and a second latch clock signal. The logically combining action includes applying a delay of less than one clock cycle to the shaped oscillator clock signal to generate a delayed oscillator clock signal; logically combining the delayed oscillator clock signal with a second signal so as to generate the first latch clock signal; and logically combining the shaped oscillator clock signal with a third signal so as to generate the second latch clock signal.

Abstract: In a method of generating clock signals for a level-sensitive scan design latch, at least one test input signal is transmitted to a plurality of splitter leaves. Once the test input signal is stabilized at each of the splitter leaves, generating a shaped oscillator clock signal having a predetermined pattern of pulses from a central root is generated. At the plurality of splitter leaves, the test input signal is logically combined with the shaped oscillator clock signal, thereby generating a first latch clock signal and a second latch clock signal. The logically combining action includes applying a delay of less than one clock cycle to the shaped oscillator clock signal to generate a delayed oscillator clock signal; logically combining the delayed oscillator clock signal with a second signal so as to generate the first latch clock signal; and logically combining the shaped oscillator clock signal with a third signal so as to generate the second latch clock signal.