A combinational circuit block has input pins configured to receive input digital signals and output pins configured to provide output digital signals as a function of the input digital signals received. A test input pin receives a test input signal. A test output pin provides a test output signal as a function of the test input signal received. A set of scan registers are selectively coupled to either the combinational circuit block or to one another so as to form a scan chain of scan registers serially coupled between the test input pin and the test output pin. The scan registers in the set of scan registers are clocked by a clock signal. At least one input register is coupled between the test input pin and a first scan register of the scan chain. The at least one input register is clocked by an inverted replica of the clock signal.

During functional/normal operation of an integrated circuit including multiple independent processing elements, a selected independent processing element is taken offline and the functionality of the selected independent processing element is then tested while the remaining independent processing elements continue functional operation. To minimize voltage drops resulting from current fluctuations produced by the testing of the processing element, clocks used to synchronize operations within each partition of a processing element are staggered. This varies the toggle rate within each partition of the processing element during the testing of the processing core, thereby reducing the resulting voltage drop. This may also improve test quality within an automated test equipment (ATE) environment.

A clock self-testing method and circuit. The clock self-testing method includes introducing a first clock signal and a second clock signal, counting cycles of the first clock signal and the second clock signal respectively beginning at the same moment, and if one of the number of cycles of the first clock signal being counted and the number of cycles of the second clock signal being counted is equal to N, determining whether the remained number of cycles is in a count range from M to N. If the remained number of cycles is out of the count range from M to N, the first clock signal and the second clock signal have errors.

A self-test mechanism within an integrated circuit to test for faulty operation of a clock monitor unit implemented within the integrated circuit for monitoring a clock signal. The mechanism intentionally injects faults into the clock monitor unit to evaluate if the clock monitor unit is operating in accordance with its specified operating parameters. The injected faults are intended to cause the clock monitor unit to determine that the clock signal is operating outside of an artificially generated, imaginary specified frequency range. If the injected faults do not cause the clock monitor unit to determine that the clock signal is operating both above and below the artificially generated, imaginary specified frequency range, then the clock monitor unit is not functioning according to specified operating parameters.

A semiconductor device includes a clock circuit that outputs a clock signal of a first frequency, a detection circuit that detects occurrence of power supply noise and end of the power supply noise, and a control circuit. The control circuit drops, in a case where the occurrence of the power supply noise is detected, a frequency of the clock signal from the first frequency to a second frequency, determine a frequency return time according to a noise occurrence time from the occurrence of the power supply noise to the end of the power supply noise, and returns the frequency of the clock signal from the second frequency to the first frequency on the basis of the frequency return time.

Testing clock division circuitry includes generating pseudo random test pattern bits for scan chain logic in programmable clock division logic circuitry and divided clock counter circuitry. A shift clock is used to shift the test pattern bits into the scan chain logic. A capture clock signal is used in the programmable clock division logic during a non-test mode of operation. The shift clock is used to provide output shift bits from the scan chain logic to a multi-input shift register (MISR). Once all the output shift bits for the test pattern bits are provided to the MISR, a final test signature from the MISR is compared to an expected test signature to determine whether the programmable clock division logic circuitry and divided clock counter circuitry are free of faults.

The present disclosure describes a method for analyzing signal waveforms produced by integrated circuits. The method includes determining characteristic points of a control signal, and each characteristic point includes a corresponding time value and represents an edge change of the control signal. The method also includes determining sets of data sampling points. Each set of data sampling points is located between adjacent characteristic points of the characteristic points. The method further includes obtaining data values of a signal waveform, and a data value of the signal waveform is obtained at a data sampling point of the sets of data sampling points. The method further includes obtaining data values of a reference waveform, and a data value of the reference waveform is obtained at the data sampling point and determining a difference between the data value of the signal waveform and the data value of the reference waveform.

An oscillation period detection circuit and method, and semiconductor memory are provided. The oscillation period detection circuit includes an oscillator module, a control module, and a counting module. The oscillator module includes a target oscillator, and is configured to receive an enable signal and control the target oscillator to output an oscillation clock signal according to the enable signal; the control module is configured to receive the enable signal and the oscillation clock signal, and perform valid time reforming processing according to the oscillation clock signal and the enable signal to determine a target time; the counting module is configured to receive the enable signal and the oscillation clock signal, and perform period counting processing according to the enable signal and the oscillation clock signal to determine a target period number. The oscillation period of the target oscillator is calculated according to the target time and the target period number.

A detection circuit configured to detect whether timing violations occur in a target circuit. The target circuit is operated according a clock signal. The detection circuit includes a signal generation circuit, a first delay adjustable circuit, a second delay adjustable circuit, and a signal detector. The signal generation circuit is configured to generate a test signal. The first and second delay adjustable circuit are respectively configured to delay the test signal and clock signal to generate a first delay signal and a second delay signal according to the operating speed of the target circuit. The signal detector is configured to generate an indicating signal according to the first delay signal, the second delay signal, the test signal, and the clock signal. The indicating signal is configured to indicate whether an operating voltage of the target circuit causes a hold time violation of timing violations to occur in the target circuit.

Testing of an electrical device is achieved by providing a test access mechanism within the device that can receive scan frames from an external tester. The received scan frames contain stimulus data to be applied to circuitry within the device to be tested, a command for enabling a test control operation, and a frame marker bit to indicate the end of the scan frame pattern. The inputting of scan frames can occur continuously and simultaneous with a commanded test control operation.