Abstract: A method and apparatus for loading a ring of non-scan latches for a logic built-in self-test. A logic built-in self-test value is loaded into a scannable latch from the logic built-in self-test. An override control signal is asserted in response to loading the logic built-in self-test value into the scannable latch. A non-scan latch is forced to load the logic built-in self-test value from the scannable latch in response to asserting the override control signal. Logic paths in the ring of non-scan latches are exercised. The non-scan latch is part of the logical paths. The test results are captured from the logic paths and the test results are compared against expected test results to determine if the logic paths within the ring of non-scan latches are functioning properly.

Abstract: Systems and methods for performing logic built-in self-tests (LBISTs) in which an LBIST controller provides control signals to multiple LBIST satellites that are co-located with different functional blocks of the device under test, such as processor cores in a multiprocessor integrated circuit. Because the data paths for each satellite are shorter than data paths in conventional LBIST architectures, fewer latches are needed to synchronize the delivery of data to scan chains in the satellites. In one embodiment, each satellite includes a pseudorandom bit pattern generator (PRPG,) scan chains and a multiple-input signature register (MISR). In one embodiment, the LBIST circuitry also includes a control scan chain that is coupled to each of the LBIST satellites and configured to scan data into and out of the LBIST satellites.

Abstract: The present invention provides for a method for memory array verification. Initialization commands are received and memory array initialization settings are generated based on received initialization commands. The memory array initialization settings are stored in a memory array. A deterministic read output function for the memory array is identified and a logic built-in self test scan on the memory array is performed based on the identified deterministic read output function.

Abstract: In a first aspect, a first method is provided that includes the steps of (1) transmitting a first signal representative of a test operation from a test circuit to a memory via a first signal path; (2) transmitting a second signal, synchronized with the first signal, from the test circuit to the memory via a second signal path; and (3) initiating the test operation on the memory in response to the second signal arriving at the memory. Numerous other aspects are provided.

Abstract: A test apparatus and a method for testing an integrated circuit's data storage device's input/output signal pins for alternating current (AC) defects, by providing an interface that will couple each respective individual test contact, in a subset of said contacts, to a select plurality of the data storage input/output signal pins so that when a selected data string is introduced into the integrated circuit so that each input/output pin on a data storage device in the integrated circuit will be tested in sequence whereby the number of contacts required by the tester can be reduced.

Abstract: Systems and methods for improved performance of built-in-self-tests (BISTs) in integrated circuits, where variability is introduced into the self tests to improve the coverage of the tests. In one embodiment, an LBIST system includes scan chains interposed between levels of functional logic in a circuit under test. An exemplary method includes the steps of, for each of one or more initial scan chains, filling the initial scan chains with data comprising a pseudorandom pattern of bits, determining a number of levels of functional circuitry and corresponding subsequent scan chains through which to propagate the data and propagating the data from the initial scan chains through the determined number of levels of functional circuitry and corresponding subsequent scan chains. The number of levels of circuitry through which data is propagated is varied from one test cycle to another based upon a pseudorandom input signal.