Disclosed herein are exemplary methods, apparatus, and systems for performing timing-aware automatic test pattern generation (ATPG) that can be used, for example, to improve the quality of a test set generated for detecting delay defects or holding time defects. In certain embodiments, timing information derived from various sources (e.g. from Standard Delay Format (SDF) files) is integrated into an ATPG tool. The timing information can be used to guide the test generator to detect the faults through certain paths (e.g., paths having a selected length, or range of lengths, such as the longest or shortest paths). To avoid propagating the faults through similar paths repeatedly, a weighted random method can be used to improve the path coverage during test generation. Experimental results show that significant test quality improvement can be achieved when applying embodiments of timing-aware ATPG to industrial designs.

A method or system for estimating delays in design under tests (DUTs) using machine learning. The system accesses multiple DUTs, each comprising various logic blocks. For each DUT, a combinatorial path is identified, connecting one or more logic blocks. A feature vector is generated, including values of orthogonal features representing the combinatorial path's characteristics. Each DUT is compiled for emulation, and the delay of its combinatorial path is measured. These measured delays, along with the corresponding feature vectors, are used to train a machine learning delay model. The trained model is designed to receive a combinatorial path of a DUT as input and generate an estimated wire delay as output. This approach leverages machine learning to predict delays in electronic designs, improving the efficiency and accuracy of delay estimations in complex circuits.

Disclosed is a fan-out buffer which includes a first channel that includes a first delay circuit adjusting a first delay time of a calibration test signal depending on a first delay control signal, a second channel that includes a second delay circuit adjusting a second delay time of the calibration test signal depending on a second delay control signal, a first edge-to-pulse converter that detects a first edge included in a first time domain reflectometry (TDR) waveform of an output terminal of the first channel and generates a first start pulse signal including a first pulse, a second edge-to-pulse converter that generates a second start pulse signal including a second pulse, a stop pulse signal generator that generates a stop pulse signal including a first stop pulse, and a first delay control signal generator that calculates a phase difference generates the first delay control signal.

A semiconductor device, a semiconductor system, and a control method of a semiconductor device are capable of accurately monitoring the lowest operating voltage of a circuit to be monitored. According to one embodiment, a monitor unit of a semiconductor system includes a voltage monitor that is driven by a second power supply voltage different from a first power supply voltage supplied to an internal circuit that is a circuit to be monitored and monitors the first power supply voltage, and a delay monitor that is driven by the first power supply voltage and monitors the signal propagation period of time of a critical path in the internal circuit.

A software-defined linear feedback shift register (SLFSR) implements a low-power test compression for launch-on-capture (LOC). Each bit of an extra register controls a stage of the SLFSR. A control vector is shifted into the extra register to indicate whether a primitive polynomial contains the stage of the non-zero bit. Therefore, SLFSR can configure any primitive polynomials with different degrees by loading different control vectors without any hardware overhead. A low-power test compression method and design for testability (DFT) architecture provide LOC transition fault testing by using seed encoding scheme, low-power test application procedure and a software-defined linear-feedback shift-register (SLFSR) architecture. The seed encoding scheme generates seeds for all test pairs by selecting a primitive polynomial that encodes all test pairs of a compact test set.

Adjustable integrated circuits and methods for designing the same are provided. In one embodiment, a method of designing an integrated circuit includes determining a plurality of design criteria of the integrated circuit; designing a plurality of circuit blocks of the integrated circuit in accordance with the plurality of design criteria, where one or more circuit blocks in the plurality of circuit blocks include one or more feedback paths; designing a circuit performance monitor, where the circuit performance monitor includes one or more replica feedback paths corresponding to the one or more feedback paths in the one or more circuit blocks, and where the circuit performance monitor is configured to monitor feedback path information of the one or more replica feedback paths; verifying the plurality of circuit blocks and the circuit performance monitor to meet the plurality of design criteria; and producing a verified description of the integrated circuit for manufacturing.

Implementing a circuit design may include detecting, using computer hardware, a net of the circuit design with a hold timing violation, generating, using the computer hardware, a list including each load of the net, and filtering, using the computer hardware, the list based on predetermined criteria by, at least in part, removing each load from the list determined to be non-critical with respect to hold timing. Using the computer hardware, the circuit design is modified by inserting a flip-flop in the net to drive each load remaining on the list, clocking the flip-flop with a clock signal of a start point or an end point of a path traversing the net, and triggering the flip-flop with an opposite clock edge compared to the start point or the end point.

An electronic system test method, comprising: (a) inputting a victim test pattern to a victim signal path of a target electronic system and simultaneously inputting at least one aggressor test pattern to at least one aggressor signal path of the target electronic system, according to a major set of test patterns comprising a plurality of minor set of test patterns; (b) acquiring a output response corresponding to the step (a); and (c) after changing the victim test pattern or the aggressor test pattern, and after repeating the step (a) and the step (b) until all of the major test patterns set are used thereby acquiring a plurality of the output responses, determining a combination level according to the output responses. The victim test pattern is an X bit pattern and the aggressor test pattern is a Y bit pattern, X and Y are positive integers larger than or equal to 3.

A measurement system may measure a fractional time delay of transmission of a signal across a medium, such as a cable. The system may use a first clock to assist in creating and injecting an injected sequence (signal) into the medium. A second, slower clock may be used for sampling the sequence after transmission of the sequence through the medium. This causes a time Vernier scale effect that results in a sampled sequence that has a one-step skip for each instances of the sequence, where the sequence has N elements in the sequence. The location of the skip within the sequence will depend on the magnitude of the delay measured as a fraction of a clock period with a resolution of N. To measure this delay, a modified version of a pseudo-random sequence generator, capable of skipping one step, is used to determine the output.

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.