Silicon test structures are described that enable separate measurement of n-channel metal-oxide semiconductor (NMOS) and p-channel metal-oxide semiconductor (PMOS) transistor delays. NMOS and PMOS specific non-inverting stages may be used to construct a multi-stage ring oscillator. Each of the non-inverting stages generates either a rising or falling primary transition that is determined by either NMOS or PMOS transistors, respectively. The opposing transition for a particular non-inverting stage is triggered by propagation of the primary transition to a subsequent non-inverting stage (producing a “reset” pulse). A frequency of the ring oscillator is determined by the primary transition and one transistor type (NMOS or PMOS). Specifically, the frequency is determined by the propagation delay of the primary transition through the entire ring oscillator.

Systems, methods, and circuits for determining a duty cycle of a periodic input signal are provided. A delay element is configured to delay the periodic input signal based on a digital control word. A digital circuit is configured to generate a first digital control word used to delay the periodic input signal a first amount of time corresponding to a period of the periodic input signal, generate a second digital control word used to delay the periodic input signal a second amount of time corresponding to a portion of the periodic input signal having a logic-level high value, and generate a third digital control word used to delay the periodic input signal a third amount of time corresponding to a portion of the periodic input signal having a logic-level low value. A controller is configured to determine the duty cycle based on the first, second, and third digital control words.

Introduced herein is a technique that reliably measures on-die noise of logic in a chip. The introduced technique places a noise measurement system in partitions of the chip that are expected to cause the most noise. The introduced technique utilizes a continuous free-running clock that feeds functional frequency to the noise measurement circuit throughout the noise measurement scan test. This allows the noise measurement circuit to measure the voltage noise of the logic during a shift phase, which was not possible in the conventional noise measurement method. Also, by being able to measure the voltage noise during a shift phase and hence in both phases of the scan test, the introduced technique can perform a more comprehensive noise measurement not only during ATE testing but as part of IST in the field.

A circuit and a method for reducing interference of power on/off to hardware test. The circuit includes: a power unit, a voltage processing unit, a PSU and a to-be-tested hardware. An input terminal of the voltage processing unit is connected to the power unit, an output terminal of the voltage processing unit is connected to an input terminal of the PSU, and an output terminal of the PSU is connected to the to-be-tested hardware; the power unit is configured to provide an operating voltage; the voltage processing unit is configured to eliminate electric sparks caused by instability of the operating voltage at an instant of power on/off; the PSU is configured to convert a stable operating voltage outputted from the voltage processing unit into a direct current voltage required for the to-be-tested hardware; and the to-be-tested hardware is configured to receive the direct current voltage outputted from the PSU.

Described is an apparatus which comprises: a first voltage regulator (VR) having a reference input node; and a first multiplexer to provide a reference voltage to the reference input node and operable to select one of at least two different reference voltages as the reference voltage.

Systems, methods, and computer readable medium described herein relate to techniques for characterizing and/or anomaly detection in integrated circuits such as, but not limited to, field programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). In one example aspect of certain example embodiments, a fully digital technique relies on the pulse width of signals propagated through a path under test. In another example aspect, the re-configurability of the integrated circuit is leveraged to combine the pulse propagation technique with a delay characterization technique to yield better detection of certain type of Trojans and the like. Another example aspect provides for running the test through reconfigurable path segments in order to isolate and identify anomalous circuit elements. Yet another example aspect provides for performing the characterization and anomaly detection without requiring golden references and the like.

The disclosure provides a delay estimation device and a delay estimation method. The delay estimation device includes a pulse generator, a digitally controlled delay line (DCDL), a time-to-digital converter (TDC), and a control circuit. The pulse generator receives a reference clock signal, outputs a first clock signal in response to a first rising edge of the reference clock signal, and outputs a second clock signal in response to a second rising edge of the reference clock signal. The DCDL receives the first clock signal from the pulse generator and converts the first clock signal into phase signals based on a combination of delay line codes. The TDC samples the phase signals to generate a timing code based on the second clock signal. The control circuit estimates a specific delay between the first clock signal and the second clock signal based on the timing code.

A full-path circuit delay measurement device for a field-programmable gate array (FPGA) and a measurement method are provided. The measurement device includes two shadow registers and a phase-shifted clock, where the two shadow registers take an output of a measured combinational logic circuit as a clock and sample the phase-shifted clock SCLK as data; the two shadow registers are respectively triggered on rising and falling edges of the output of the measured combinational logic circuit to sample the phase-shifted clock; outputs of the two shadow registers are delivered by an OR gate as an input into a synchronization register; a clock of the synchronization register serves as a clock MCLK of the measured combinational logic circuit; an output of the synchronization register serves as that of the circuit delay measurement device; the phase-shifted clock SCLK and the clock MCLK of the measured combinational logic circuit have the same frequency.

This disclosure describes a test architecture that supports a common approach to testing individual die and dies in a 3D stack arrangement. The test architecture uses an improved TAP design to facilitate the testing of parallel test circuits within the die.

A logic analyzer includes a probe, an FPGA module, a first transmission interface, a storage module, and a second transmission interface. A method of retrieving data includes the following steps: retrieve a digital signal through the probe, integrate the digital signal into a piece of signal data through the FPGA module, receive the signal data through the first transmission interface, save the signal data in the storage module through the first transmission interface with a first transmission rate, return the signal data saved in the storage module to the FPGA module through the first transmission interface, receive and transmit the signal data to the computer through the second transmission interface with a second transmission rate, whereby to save the signal data therein. A method of performance testing includes testing multiple objects to correspondingly generate a response time triggered by a digital signal, whereby to analyze the performance of the objects.