摘要:
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.
摘要:
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.
摘要:
Systems and methods for performing logic built-in self-tests (LBISTs) in digital circuits, where boundary scan chains in functional blocks of the circuits can be selectively coupled/decoupled to isolate the functional blocks during LBIST testing. In one embodiment, processor cores of a multiprocessor chip are isolated and LBIST testing is performed to determine whether any of the processor cores is malfunctioning. If none of the processor cores malfunctions, the processor cores are tested in conjunction with the supporting functional blocks of the device to determine whether the multiprocessor is fully functional. If one or more processor cores malfunctions, these processor cores are isolated and the remaining processor cores are tested in conjunction with the supporting functional blocks of the device to determine whether the multiprocessor operates properly with reduced functionality.
摘要:
The present invention provides an apparatus and a computer program product for applying external clock and data patterns for TTP-LBIST. A simulation model for the logic under test is set up in a simulator. Next, a user sets up an external LBIST block, which comprises pre-verified internal clock and data pattern logic, and connects this block to the logic in the simulation model. The internal clock and data pattern logic provides the input patterns used in OPCG modes of LBIST. This internal clock and data pattern logic is already verified through the design effort. Therefore, the internal pattern generators become the external pattern generators in the simulation model. The external LBIST block applies the external clock and data patterns, and subsequently, the user receives and processes these output patterns to determine if the logic operates correctly.
摘要:
Systems and methods for performing logic built-in-self-tests (LBISTs) in digital circuits, where the LBIST circuitry is configured to propagate data through different portions of the functional logic of the circuits at different times. In one embodiment, a logic circuit incorporates LBIST components including a set of scan chains interposed between portions of the functional logic. Pseudorandom bit patterns are scanned into the scan chains so that they can be propagated through the functional logic following the scan chains. The resulting bit patterns are captured in scan chains following the functional logic and then scanned out of these scan chains. An LBIST controller causes functional operations in different portions of the functional logic to be performed at different times during a functional phase of a test cycle. The functional operations may be performed at a normal operating speed, while scan shift operations may be performed at a lower speed.
摘要:
Systems and methods for performing logic built-in self-tests (LBISTs) in digital circuits, where boundary scan chains in functional blocks of the circuits can be selectively coupled/decoupled to isolate the functional blocks during LBIST testing. In one embodiment, processor cores of a multiprocessor chip are isolated and LBIST testing is performed to determine whether any of the processor cores is malfunctioning. If none of the processor cores malfunctions, the processor cores are tested in conjunction with the supporting functional blocks of the device to determine whether the multiprocessor is fully functional. If one or more processor cores malfunctions, these processor cores are isolated and the remaining processor cores are tested in conjunction with the supporting functional blocks of the device to determine whether the multiprocessor operates properly with reduced functionality.
摘要:
Systems and methods for performing logic built-in self-tests (LBISTs) in digital circuits. In one embodiment, a system has first and second target logic, each of which has LBIST circuitry incorporated therein. The system also includes comparison circuitry which is coupled to the first and second LBIST circuitry. The comparison circuitry is configured to detect differences between data generated by the LBIST circuitry of the first target logic and data generated by the LBIST circuitry of the second target logic (e.g., MISR signature values.) The comparison circuitry is also configured to provide information localizing the sources of the differences. In one embodiment, this localizing information comprises values from a test cycle counter, a scan shift counter and a set of XOR gates that compare the bits of the MISR values.
摘要:
Systems and methods for performing logic built-in-self-tests (LBISTs) in digital circuits, where scan shift operations of the LBIST circuitry are performed at reduced rates. In one embodiment, a base clock signal is gated before being provided to LBIST circuitry. The clock signal is gated to produce an effective clock rate that is reduced in one or more steps from a first rate that is used in a functional phase of LBIST testing to a reduced rate that is used in a scan shift phase. The effective clock rate is stepped back up at the end of the scan shift phase to the first rate which is used in the following functional phase.
摘要:
A method for testing an electronic circuit includes selecting an input signal using a first multiplexer, selecting a signal to be input to the first multiplexer using at least one other multiplexer, and controlling the at least one other multiplexer using a selection signal output from a control circuit.
摘要:
A data transfer circuit includes: an asynchronous memory to which transfer data is written from a first clock domain with a first clock and from which the written transfer data is read to a second clock domain with a second clock; a scan flip-flop whose input terminal is connected to a first position located on a data path, of the transfer data, from the asynchronous memory to the second clock domain, and whose output terminal is connected to a second position located on a data path, of the transfer data, from the asynchronous memory to the first position; and a clock selector which selects a clock to drive the scan flip-flop from the first clock and the second clock.