A series of pseudo-random test patterns provide inputs to a logic circuit for performing logic built-in self test (LBIST). A weight configuration module applies one or more weight sets to the pseudo-random test patterns, to generate a series of weighted pseudo-random test patterns. A logic analyzer determines a probability expression for each given net of the logic circuit, based on associated weight sets and a logic function performed by the net. A probability module computes an output probability for each net based on associated probability expressions and associated input probabilities. The weight configuration module optimizes the weight sets, based on the computed net probabilities, and further based on a target probability range bounded by lower and upper cutoff probabilities.

A circuit comprises: a bit-flipping signal generation device comprising a storage device and configured to generate a bit-flipping signal based on bit-flipping location information, the storage device configured to store the bit-flipping location information for a first number of bits, the bit-flipping location information obtained through a fault simulation process; a pseudo random test pattern generator configured to generate test patterns based on the bit-flipping signal, the pseudo random test pattern generator comprising a register configured to be a linear finite state machine, the register comprising storage elements and bit-flipping devices, each of the bit-flipping devices coupled to one of the storage elements; and scan chains configured to receive the test patterns, wherein the bit-flipping signal causes one of the bit-flipping devices to invert a bit of the register each time a second number of test patterns is being generated by the pseudo random test pattern generator during a test.

An approach for testing, including a self-test method, a semiconductor chip is disclosed. The approach generates test patterns, including weighted random test patterns, for testing random pattern resistant faults, and un-modeled faults directed at specific logic groups, where the dynamically generated test pattern weights are configured to optimize test coverage and test time. The dynamically generated test patterns are based on factors related to random pattern resistant logic structures interconnected via scan chains. More particularly, the dynamically generated test patterns are designed to enable fault detection within logic structures that are resistant to fault detection when tested with random patterns.

A series of pseudo-random test patterns provide inputs to a logic circuit for performing logic built-in self test (LBIST). A weight configuration module applies one or more weight sets to the pseudo-random test patterns, to generate a series of weighted pseudo-random test patterns. A logic analyzer determines a probability expression for each given net of the logic circuit, based on associated weight sets and a logic function performed by the net. A probability module computes an output probability for each net based on associated probability expressions and associated input probabilities. The weight configuration module optimizes the weight sets, based on the computed net probabilities, and further based on a target probability range bounded by lower and upper cutoff probabilities.

An integrated circuit chip includes a plurality of function blocks; a mode controller configured to convert an input signal, received from an external device through an input/output pin, into an input pattern and test mode setting data which include a plurality of bits, and to output the test mode setting data and a mode switching enable signal when a secure pattern generated therein is the same as the input pattern; and a mode setting module configured to control the plurality of function blocks to operate in a test mode according to the mode setting data, in response to the test mode switching enable signal.

An integrated circuit (IC) includes logic components and a scan test circuit coupled to the logic components. The IC also includes a scan input pin coupled to the scan test circuit. The IC also includes a scan input/output pin coupled to the scan test circuit. The scan test circuit includes a decoder coupled to at least one of the scan input pin and the scan input/output pin. The decoder includes storage elements configured to store different scan control signals and to output at least one of the different scan control signals in response to a master control signal.

Accordingly, an improved interposer connection testing technique is provided, employing parallel pseudo-random bit sequence (PRBS) generators to test all the interconnects in parallel and simultaneously detect any correctable defects. In one embodiment, a microelectronic assembly includes an interposer electrically connected in a flip-chip configuration to an originating IC (integrated circuit) die and to a destination IC die, the substrate having multiple conductive traces for a parallel communications bus between the IC dies. The originating IC die has a first parallel PRBS (pseudo-random binary sequence) generator to drive test PRBSs with different phases in parallel across the interposer traces. The destination IC die has a second parallel PRBS generator to create reference PRBSs with different phases, and a bitwise comparator coupled to receive the test PRBSs from the interposer traces and to compare them to the reference PRBSs to provide concurrent fault monitoring for each of the traces.

An integrated circuit (IC) includes logic components and a scan test circuit coupled to the logic components. The IC also includes a scan input pin coupled to the scan test circuit. The IC also includes a scan input/output pin coupled to the scan test circuit. The scan test circuit includes a decoder coupled to at least one of the scan input pin and the scan input/output pin. The decoder includes storage elements configured to store different scan control signals and to output at least one of the different scan control signals in response to a master control signal.

A scan chain may be formed throughout an integrated circuit in which the scan chain is coupled to a set of pins via bi-directional input/output (I/O) buffers. A state machine may be provided to control the scan chain. Decoding logic may monitor states and transitions between states and generate pseudo static control signals in response to certain states and transition sequences in order to free up test pins for use as additional scan data I/O pins using a single JTAG IR. A test pattern may be received from an external tester using the set of I/O pins and buffers operating in parallel. The test pattern may then be provided to combinatorial logic circuitry coupled to the scan chain. A response pattern may be captured in the scan chain. The response pattern may then be provided to the external tester using the same set of I/O pins and buffers operating in parallel.

Embodiments of the invention are directed to a built-in self-test system for an electronic circuit. The system includes a memory having two or more base seeds stored thereon. The system further includes seed generation logic configured to generate, based at least in part on the two or more base seeds, a plurality of generated seeds. The generated seeds can be constructed from the base seeds such that each of the generated seeds encodes a test pattern that satisfies a functional constraint. A finite state machine is configured to generate, based on the plurality of generated seeds, a sequence of constrained pseudorandom test patterns. A test controller is operable to place the electronic circuit into a test mode based on the constrained pseudorandom test pattern.