A system is provided that includes a memory configured to store test patterns. A first lockstep core and a second lockstep core are configured to receive the same set of test patterns. First scan outputs are generated from the first lockstep core, and second scan outputs are generated from the second lockstep core during a reset of the first lockstep core and the second lockstep core. A comparator can be coupled to the first lockstep core and the second lockstep core and is configured to compare the first scan outputs to the second scan outputs. The first and second lockstep cores can be initialized to a similar state if the first and second scan outputs are the same. The first and second lockstep cores can comprise non-resettable flip flops.

A semiconductor device addresses to a problem in which a current consumption variation rate increases during BIST execution causing resonance noise generation in a power supply line. The semiconductor device includes a self-diagnosis control circuit, a scan target circuit including a combinational circuit and a scan flip-flop, and an electrically rewritable non-volatile memory. A scan chain is configured by coupling a plurality of the scan flip-flops. In accordance with parameters stored in the non-volatile memory, the self-diagnosis control circuit can change a length of at least one of a scan-in period, a scan-out period and a capture period, and can also change a scan start timing.

An integrated circuit (IC) includes first and scan latches that are enabled to load data during a first part of a clock period. A clocking circuit outputs latch clocks with one latch clock driven to an active state during a second part of the clock period dependent on a first address input. A set of storage elements have inputs coupled to the output of the first scan latch and are respectively coupled to a latch clock to load data during a time that their respective latch clock is in an active state. A selector circuit is coupled to outputs of the first set of storage elements and outputs a value from one output based on a second address input. The second scan latch then loads data from the selector's output during the first part of the input clock period.

A logic gate system for fault insertion testing can include a logic gate module having a plurality of input pins. The plurality of input pins can include an input signal pin configured to receive an input signal, a power supply input pin configured to receive power from a power supply, and a test input pin. The logic gate module can also include an output pin connected to the input pins via one or more logic gates. The logic gate system can include a power supply line connected to the power supply input pin and the test input pin. The logic gate system can also include a zero-ohm jumper resistor disposed between the power supply input pin and the test input pin. The zero-ohm resistor can be configured to be replaced with a low ohm resistor to allow reverse driving a voltage on the test input pin. The one or more logic gates can be configured to reverse an output at the output pin when the voltage on the test input pin is reverse driven.

In one embodiment, a device comprises: a first die having disposed thereon a first plurality of latches wherein ones of the first plurality of latches are operatively connected to an adjacent one of the first plurality of latches; and a second die having disposed thereon a second plurality of latches wherein ones of the second plurality of latches are operatively connected to an adjacent one of the second plurality of latches. Each latch of the first plurality of latches on said first die corresponds to a latch in the second plurality of latches on said second die. Each set of corresponding latches are operatively connected. A scan path comprises a closed loop comprising each of said first and second plurality of latches. One of the second plurality of latches is operatively connected to another one of the second plurality of latches via an inverter.

A semiconductor device comprises a plurality of memory elements, test control circuitry, and a testing interface. The test control circuitry is configure to determine that one or more clock signals associated with the memory elements have been stopped and generate a scan clock signal based on the determination that the one or more clock signals have been stopped. The test control circuitry is further configured to communicate the scan clock signal to the memory elements. The testing interface is configured to communicate test data from the memory elements. In one example, the test data is delimited with start and end marker elements. The semiconductor device is mounted to a circuit board and is communicatively coupled to communication pins of the circuit board.

A circuit system includes a first circuit, a second circuit, and a comparator. The second circuit and the first circuit have substantially identical structures. In a testing mode, the circuit system controls the first circuit and the second circuit to perform the same testing operation synchronously. During the process of the testing operation, the comparator keeps compares a first intermediate signal internally generated by the first circuit and a second intermediate signal corresponding to the first intermediate signal that is internally generated by the second circuit. When the first intermediate signal is different from the second intermediate signal, the circuit system controls the first circuit and the second circuit to stop the testing operation and controls the first circuit and the second circuit to perform a scan dump operation in order to record signals transmitting by the first circuit and signals transmitting by the second circuit.

A tool for performing a logic built-in self-test of an electronic circuit operating on a clock cycle basis. The tool stores a configurable test signature in a random-access memory together with a pattern counter for a test pattern, wherein a number of the at least one additional signature register corresponds to a number of entries in the random access memory. The tool determines an error based, at least in part, on a compare operation for a given test pattern, wherein the compare operation determines whether the test signature in the first signature register before a capture cycle of a next test pattern differs from the corresponding configurable test signature. The tool stores the error in a corresponding additional signature register.

The present disclosure describes exemplary methods and systems that are applicable for hardware authentication, counterfeit detection, and in-field tamper detection in both printed circuit board and/or integrated circuit levels by utilizing random variations in boundary-scan path delay and/or current in the industry-standard JTAG-based design-for-test structure to generate unique device identifiers.

A control system, that includes a primary controller and various auxiliary controllers, is configured to facilitate a built-in self-test (BIST) of a system-on-chip (SoC). The primary controller is configured to initiate a BIST sequence associated with the SoC. Based on the BIST sequence initiation, each auxiliary controller is configured to schedule execution of various self-test operations on various functional circuits, various memories, and various logic circuits of the SoC by various functional BIST controllers, various memory BIST controllers, and various logic BIST controllers of the SoC, respectively. Based on the execution of the self-test operations, each auxiliary controller further generates various status bits with each status bit indicating whether at least one functional circuit, at least one memory, or at least one logic circuit is faulty. Based on the status bits generated by each auxiliary controller, a fault diagnosis of the SoC is initiated.