Abstract: A method for verifying the accuracy of memory testing software is disclosed. A built-in self test (BIST) fail control function is utilized to generate multiple simulated memory fails at various predetermined locations within a memory array of a memory device. The memory array is then tested by a memory tester. Afterwards, a bit fail map is generated by the logical-to-physical mapping software based on all the memory fails indicated by the memory tester. The bit fail map provides all the fail memory locations derived by the logical-to-physical mapping software. The fail memory locations derived by the logical-to-physical mapping software are then compared to the predetermined memory locations to verify the accuracy of the logical-to-physical mapping software.

Abstract: A method and apparatus for preventing the overwriting of memory contents during certain scan operations is disclosed. An integrated circuit (IC) may include a memory and a scan chain having a number of serially coupled scan elements. A number of the scan elements may be coupled to circuitry for inputting signals to or receiving signals output from the memory. An inhibit circuit may also be coupled to the circuitry for inputting signals to the memory. During scan shifting operations commensurate with a scan dump mode or a memory dump mode, the inhibit circuit may de-assert one or more control signals that otherwise enable access to the memory in order to prevent shifted data from overwriting the contents stored in the memory. The apparatus may also include a bypass unit coupled to a memory read port, which can be activated to prevent unauthorized access to protected data stored in the memory.

Abstract: A built-in self test (BiST) system is described. The BiST system includes a circuit-under-test. The BiST system also includes one or more embedded sensors. Each of the embedded sensors includes one or more switches connected to one or more nodes within the circuit-under-test. The BiST system further includes a signal generator. The BiST system also includes a bus interface. The bus interface provides for external access of the BiST system.

Abstract: An integrated circuit chip that supports stored-pattern (SP) logic built-in self-testing (LBIST) includes a device under test (DUT) and a test controller. System-level SP LBIST testing is performed using an external, system ATE (automated test equipment) that transmits test input data to the test controller for application to the DUT, which generates test output data that is transmitted from the test controller to the system ATE, which performs golden signature comparisons on the test output data. During system-level DUT testing, all communications between the system ATE and the chip are via a single interface, such as a conventional, serial JTAG port.

Abstract: Roughly described, a scan-based test architecture is optimized in dependence upon the circuit design under consideration. In one embodiment, a plurality of candidate test designs are developed. For each, a plurality of test vectors are generated in dependence upon the circuit design and the candidate test design, preferably using the same ATPG algorithm that will be used downstream to generate the final test vectors for the production integrated circuit device. A test protocol quality measure such as fault coverage is determined for each of the candidate test designs, and one of the candidate test designs is selected for implementation in an integrated circuit device in dependence upon a comparison of such test protocol quality measures. Preferably, only a sampling of the full set of test vectors that ATPG could generate, is used to determine the number of potential faults that would be found by each particular candidate test design.

Abstract: An architecture for testing a plurality of circuits on an integrated circuit is described. The architecture includes a TAP Linking Module located between test pins on the integrated circuit and 1149.1 Test Access Ports (TAP) of the plurality of circuits to be tested. The TAP Linking Module operates in response to 1149.1 scan operations from a tester connected to the test pins to selectively switch between 1149.1 TAPs to enable test access between the tester and plurality of circuits. The TAP Linking Module's 1149.1 TAP switching operation is based upon augmenting 1149.1 instruction patterns to affix an additional bit or bits of information which is used by the TAP Linking Module for performing the TAP switching operation.

Abstract: A system including a frame capture module, a serializer, and a deserializer. The frame capture module is configured to receive, from a device under test, data corresponding to test results, and package the data into first data frames. The serializer is configured serialize the first data frames to form serial messages that include serialized data. The serializer includes i) a first serial link configured to output the serial messages according to a first clock domain, and ii) a second serial link configured to output the serial messages according to a second clock domain. The deserializer is configured to deserialize the serial messages received on the first serial link and the second serial link to form second data frames.

Abstract: A method of testing a data connection using at least one test sequence, the method including providing a first bit sequence by a first generator; duplicating the first bit sequence to generate a second bit sequence identical to the first; and generating the at least one test sequence based on the first and second bit sequences and transmitting the at least one test sequence over a data connection to be tested.

Abstract: A Scan-BIST architecture is adapted into a low power Scan-BIST architecture. A generator 102, compactor 106, and controller 110 remain the same as in the known art. The changes between the known art Scan-BIST architecture and the low power Scan-BIST architecture involve modification of the known scan path into scan path 502, to insert scan paths A 506, B 508 and C 510, and the insertion of an adaptor circuit 504 in the control path 114 between controller 110 and scan path 502.

Abstract: A test method for an ASIC uses an embedded processor in the ASIC to execute test routines from an embedded memory or an external memory. During ASIC production, the test routines can comprehensively test of the blocks of the ASIC without a complicated test pattern from test equipment. The test routines can also perform power-up tests in systems or end products containing the ASIC. Test selection, activation, and result output can be implement using a few terminals of the ASIC.

Abstract: A computer implemented method of embedded dynamic random access memory (EDRAM) macro disablement. The method includes isolating an EDRAM macro of a cache memory bank, the cache memory bank being divided into at least three rows of a plurality of EDRAM macros, the EDRAM macro being associated with one of the at least three rows. Each line of the EDRAM macro is iteratively tested, the testing including attempting at least one write operation at each line of the EDRAM macro. It is determined that an error occurred during the testing. Write perations for an entire row of EDRAM macros associated with the EDRAM macro are disabled based on the determining.

Abstract: A data receiver device includes a logic unit configured to generate a test pattern signal, receive a test result signal in the test mode, and compare the test pattern signal with the test result signal to perform a test in the test mode. The data receiver further includes a system frequency control circuit configured to multiply a reference clock signal by a multiplication factor received from the logic unit and to output a test clock signal, an output terminal configured to serialize the test pattern signal based on the test clock signal and to output an output signal, and an input terminal configured to recover a data signal and a data clock signal from an input signal based on the output signal, to deserialize the data signal based on the data clock signal, and to output the test result signal to the logic unit.

Abstract: An on-chip functional debugger includes one or more functional blocks each providing one or more functional outputs. A hierarchical selection tree is formed by one or more selectors having the output of one of the selectors as a final output and individual selector inputs coupled either to a functional output from the functional blocks or to an output of another selector. A selection signal coupled to the select input of each of the selectors to enable a selected one of its output. An output node coupled to the final output. A method of providing on-chip functional debugging is also provided. A desired functional output from one or more available functional outputs is selected and then the selected functional output is coupled to an output node.

Abstract: A multi-core integrated circuit includes first and second sets of processor cores and corresponding first and second test access ports (TAPs). The first and second TAPs are connected to corresponding first and second debug ports by way of corresponding first and second TAP controllers. The first and second sets of processor cores include first and second memory blocks and corresponding first and second built-in-self-testing (BIST) engines of different architectures. A control circuit configures the first and second TAP controllers and the connection between the first and second sets of processor cores and the first and second debug ports, for initiating the first and second BIST engines for testing the memory blocks using a predetermined test mode. A debug access module provides secure access to the first and second debug ports.

Abstract: A semiconductor memory device includes a test mode signal generation circuit configured to generate test mode signals which are selectively enabled, in response to a test enable signal which is enabled upon entry into a test mode; and a test mode signal output circuit configured to store the test mode signals in response to an input control signal and output the test mode signals in response to an output control signal, wherein the input control signal is enabled when a test write signal is generated according to a combination of commands, and the output control signal is a signal which is generated by delaying a test read signal a preset amount of time, where the test read signal is generated according to a combination of the commands.

Abstract: Systems and methods for 1553 bus operation self checking are provided. In one embodiment, a fault tolerant computer comprises a self-checking processor pair that includes a master processor, a checking processor, and self-checking pair logic; a 1553 bus transceiver; and a device comprising 1553 self-checking logic coupled between the self-checking processor pair and the 1553 bus transceiver, wherein the 1553 self-checking logic manages data communication between the 1553 bus transceiver and the self-checking processor pair. The 1553 self-checking logic includes a primary logic and a secondary logic that operate in lock-step. When the 1553 self-checking logic writes data to the 1553 bus transceiver, the 1553 self-checking logic compares a first 1553 formatted message generated by the primary logic to a second 1553 formatted message generated by the secondary logic, and generates an error indication when the first 1553 formatted message does not match the second 1553 formatted message.

Abstract: A method of test path selection and test program generation for performance testing integrated circuits. The method includes identifying clock domains having multiple data paths of an integrated circuit design having multiple clock domains; selecting, from the data paths, critical paths for each clock domain of the multiple clock domains; using a computer, for each clock domain of the multiple clock domain, selecting the sensitizable paths of the critical paths; for each clock domain of the multiple clock domain, selecting test paths from the sensitizable critical paths; and using a computer, creating a test program to performance test the test paths.

Abstract: A method and system to automate scan synthesis at register-transfer level (RTL). The method and system will produce scan HDL code modeled at RTL for an integrated circuit modeled at RTL. The method and system comprise computer-implemented steps of performing RTL testability analysis, clock-domain minimization, scan selection, test point selection, scan repair and test point insertion, scan replacement and scan stitching, scan extraction, interactive scan debug, interactive scan repair, and flush/random test bench generation. In addition, the present invention further comprises a method and system for hierarchical scan synthesis by performing scan synthesis module-by-module and then stitching these scanned modules together at top-level. The present invention further comprises integrating and verifying the scan HDL code with other design-for-test (DFT) HDL code, including boundary-scan and logic BIST (built-in self-test).

Abstract: An integrated circuit (IC), comprises a receiver on an IC substrate. The receiver is configured to receive a stressed input signal. A built in self test (BIST) circuit is provided on the IC substrate for testing the receiver. The BIST circuit comprises an encoder configured for receiving an input signal and identifying whether a first condition is present, in which two or more consecutive input data bits have the same polarity as each other. An output driver circuit provides the stressed input signal corresponding to the two or more consecutive input data bits. The stressed input signal has an amplitude that is larger when the encoder identifies that the first condition is present and smaller when the encoder identifies that two or more consecutive input data bits have different polarity from each other.

Abstract: In a memory testing method for testing a memory module of a computing device, an operating voltage of the memory module is adjusted to a first voltage or a second voltage. A predetermined data set is written into the memory module after the operating voltage of the memory module is adjusted, and the written data set is read out from the memory module, to accomplish a data writing and reading process of the memory module. A register value that presents how many memory errors have occurred during the data writing and reading process is acquired from an ECC register of the memory module, to determine whether the memory module is stable during the adjusting of the operating voltage according to the register value.

Abstract: An integrated circuit comprises a scan chain with parallel inputs and outputs coupled to a functional circuit. A scan chain modifying circuit is provided coupled to the scan chain. When testing is authorized the scan chain modifying circuit operates in a mode wherein a normal shift path is provided through the scan chain. When testing is not authorized the scan chain modifying circuit operates to effect spontaneous dynamic changes in the shift path, which dynamically vary the length of the shift path between external terminals of the integrated circuit while shifting takes place. In an embodiment the dynamical variations are controlled by a running key comparison. In other embodiments running key comparison is used to disable transfer through the scan chain or operation of functional circuits.

Abstract: An integrated circuit carries an intellectual property core. The intellectual property core includes a test access port 39 with test data input leads 15, test data output leads 13, control leads 17 and an external register present, ERP lead 37. A scan register 25 encompasses the intellectual property core and ERP lead 37 carries a signal indicating the presence of the scan register.

Abstract: A memory system includes: a memory chip group including n chips of a nonvolatile semiconductor memory dividedly managed for each of unit areas having predetermined sizes, an unit area of one chip among the n chips storing an error correction code for a group including unit areas in the other n?1 chips associated with the unit area, and the chip that stores the error correction code being different for each of positions of the unit areas; and an access-destination calculating unit that designates, when data in the unit areas is rewritten, the unit area in which the error correction code of data is stored as a writing destination of rewriting data, and designates an unit area in which data before rewriting is stored as a storage destination of a new error correction code.

Abstract: An electronic circuit having a boundary scan test circuit receives, though one pin, an embedded clock encoded test signal having an encoded bit stream having occurrences of a first header followed by at least one encoded boundary scan mode bit and an encoded second header followed by at least one boundary scan test input bit. The bit stream and the clock are extracted and occurrences of the first header and second header are detected. Based on the detected occurrences the boundary scan mode bits and boundary scan input bits are identified and distributed to the electronic circuit, along with the extracted clock, and boundary scan test is performed.

Abstract: A method and apparatus for performing a memory dump. The method includes providing a memory location from a debugger to a memory array through a BIST wrapper, and receiving data by the debugger read from the memory location in the memory array. The method can include sending a dump enable signal from the debugger, and the BIST wrapper selectively providing the memory location to the memory array in response to the dump enable signal. The method can include sending the dump enable signal to a multiplexer coupled to a register in the BIST wrapper, the dump enable signal causing the multiplexer to load the register with the memory location. The method can include asynchronously sending a write disable signal to the memory array before reading the data from the memory location. The received data can be selected from a larger set of data read from the memory location.

Abstract: In a particular embodiment, a method is disclosed that includes mapping failing bit positions within multiple scan chains to memory locations of a memory mask. The method also includes executing logic built-in self-test (LBIST) testing on a semiconductor device using the memory mask to selectively mask certain results within the multiple scan chains. The results are associated with performance of LBIST testing on the semiconductor device.

Abstract: The disclosure describes a novel method and apparatus for providing expected data, mask data, and control signals to scan test architectures within a device using the falling edge of a test/scan clock. The signals are provided on device leads that are also used to provide signals to scan test architectures using the rising edge of the test/scan clock. According to the disclosure, device test leads serve to input different test signals on the rising and falling edge of the test/scan clock which reduces the number of interconnects between a tester and the device under test.

Abstract: Electronic apparatus, systems, and methods of operating and constructing the electronic apparatus and/or systems include an embedded processor disposed in a logic chip to direct, among other functions, self-testing of an electronic device structure in conjunction with a pattern buffer disposed in the logic chip, when the electronic device structure is coupled to the logic chip. Additional apparatus, systems, and methods are disclosed.

Abstract: An improved latch arrangement for an electronic digital system is disclosed. The latch arrangement comprises a certain number of standard latches configured as configuration-switch latches which are modified only by shift operation and/or during Error Checking and Correction (ECC) action, and a corresponding number of standard latches configured as Error Checking and Correction (ECC) latches storing Error Checking and Correction (ECC) bit data used to check latch data of said configuration-switch latches.

Abstract: Methods for at-speed testing of a memory interface associated with an embedded memory comprise two write operations in succession, two read operations in succession, and a capture operation using scan cells. The write and read operations are performed during a single clock burst, two separate clock bursts in a clock signal, or two separate clock bursts in separate clock signals.

Abstract: At least one external pin of an integrated circuit (IC) is coupled to receive a first configuration signal used in configuring an internal circuit block for a test designed to uncover faults in the circuit block, and to receive a first test signal during the test. Configuration logic in the IC is designed to generate control data by decoding configuration signals that include the first configuration signal. A test configuration register stores the control data and applies the control data during the test, but is decoupled from the configuration logic prior to commencement of the test. A sequence detector in the IC is designed to detect a reset sequence signifying an end of the test and in response to re-couple the test configuration register to the configuration logic. The number of external pins needed for testing the IC is reduced.

Abstract: The content and order of a predetermined sequence of hard-coded and/or quasi-programmable test patterns may be altered during a Built-In Self-Test (BIST) routine. As such, knowledge gained post design completion may be reflected in the selection and arrangement of available tests to be executed during a BIST routine. In one embodiment, a sequence of hard-coded and/or quasi-programmable tests is executed during a BIST routine by receiving test ordering information for the sequence of tests and executing the sequence of tests in an order indicated by the test ordering information. A corresponding BIST circuit comprises a storage element and a state machine. The storage element is configured to store test ordering information for the sequence of tests. The state machine is configured to execute the sequence of tests in an order indicated by the test ordering information.

Abstract: A method and circuit for implementing enhanced Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. A plurality of pseudo random pattern generators (PRPGs) is provided, each PRPG comprising one or more linear feedback shift registers (LFSRs). Each respective PRPG includes an XOR feedback input selectively receiving a feedback from another PRPG and predefined inputs of the respective PRPG. A respective XOR spreading function is coupled to a plurality of outputs of each PRPG with predefined XOR spreading functions applying test pseudo random pattern inputs to LBIST channels for LBIST diagnostics.

Abstract: An electronic circuit includes first and second circuits that include corresponding built-in-self-test (BIST) engines to perform memory testing operations on corresponding first and second memory block and generate first and second memory repair data. A multiplexer receives the first and second memory repair data and selectively transmits the first memory repair data during a first test cycle and the second memory repair data during a second test cycle. A shadow register buffers the first memory repair data during the first test cycle and a fuse processor sequentially receives and stores the first and second memory repair data during the second test cycle.

Abstract: A system for generating test signals to test characteristics of input-output (IO) cells includes a memory and a processor coupled together through an integrated circuit (IC) chip. The IC chip includes a controller configured to exchange signals between the memory and the processor through IO cells of the IC chip. The IC chip further includes a protocol sequence generator for generating test signals for testing characteristics of the IO cells.

Abstract: A test interface circuit couplable between a source driver and test equipment is disclosed. The test interface circuit includes a plurality of test interface modules and a logic circuit. Each of the test interface modules receives an output signal from one of a plurality of output pins of the source driver, judges whether the received output signal falls in a specified range or not, and generates a deviation signal accordingly. The logic circuit generates a deviation test output signal according to the deviation signals generated by the test interface modules.

Abstract: Error correction is selectively applied to data, such as repair data to be stored in a fusebay for BIST/BISR on an ASIC or other semiconductor device. Duplicate bit correction and error correction code state machines may be included, and selectors, such as multiplexers, may be used to enable one or both types of correction. Each state machine may include an indicator, such as a “sticky bit,” that may be activated when its type of correction is encountered. The indicator(s) may be used to develop quality and yield control criteria during manufacturing test of parts including embodiments of the invention.

Abstract: An integrated circuit chip includes a mainline function logic path communicatively connected to a first input/output (I/O) pin, a test logic path communicatively connected to the first I/O pin, a latch disposed between the communicative connection between the test logic function path and the first I/O pin, a second I/O pin communicatively connected to the latch, the second I/O pin operative to send a signal operative to change a state of the latch.

Abstract: The present invention relates to a memory with a self-test function and a method for testing the same. The memory comprises a testing unit, a memory unit, and a comparison module. The method for testing the memory comprises steps of the testing unit producing a pattern signal; a first storage block of the memory unit storing storage data, and outputting the storage data according to the pattern signal; a second storage block of the memory storing a compare signature corresponding to the storage data; and the compare module producing a test signature according to the storage data output by the memory unit, and comparing the test signature to the compare signature and outputting a testing result for judging validity of the memory unit. Thereby, the memory unit according to the present invention is partitioned into two storage blocks for storing the storage data and the compare signature, respectively, and thus achieving the purposes of saving the testing time, costs, and hardware resources.

Abstract: A mechanism is provided in an integrated circuit simulator for tracking array data contents across three-value read and write operations. The mechanism accounts for write operations with data values and address values having X symbols. The mechanism performs writes to a tree data structure that is used to store the three-valued contents to the array. The simulator includes functionality for updating the array contents for a three-valued write and to read data for a three-valued read. The simulator also includes optimizations for dynamically reducing the size of the data structure when possible in order to save memory in the logic simulator.

Abstract: Disclosed are embodiments of an integrated circuit that incorporates an asynchronous circuit with a built-in self-test (BIST) architecture using a handshaking protocol for at-speed testing to detect stuck-at faults. In the embodiments, a test pattern generator applies test patterns to an asynchronous circuit and an analyzer analyzes the output test data. The handshaking protocol is achieved through the use of a single pulse generator, which applies a single pulse to the test pattern generator to force switching of the test pattern request signal and, thereby to control application of the test patterns to the asynchronous circuit and subsequent switching of the test pattern acknowledge signal. Generation of this single pulse can in turn be forced by the switching of the test pattern acknowledge signal. Optionally, a time constraint can be added to the capture of the output test data to allow for detection of delay faults.

Abstract: Integrated circuits with memory built-in self test (MBIST) circuitry and methods are disclosed that employ enhanced features. In one aspect of the invention, MBST circuitry is used set memory elements of arrays to a first state and then to an inverse state during a burn-in operation to maintain each of the two opposing states for a desired time in order to either force a failure of the integrated circuit component or produce a pre-stressed component beyond an infancy stage. Preferably, an integrated circuit is provided having MIBST circuitry configured to serially test multiple arrays of memory elements within a component of the integrated circuit and to also conduct parallel initialization of the serially tested arrays.

Abstract: A test circuit includes a plurality of TAP controllers conforming to a standard specification defined in IEEE 1149 and includes a master TAP controller which receives a control code and a test control signal and performs a test on a circuit to be tested and which outputs a shift mode signal, a first slave TAP controller which receives the control code and the test control signal and performs a test on a circuit to be tested, and a first TAP pin control circuit provided to correspond to the first slave TAP controller and which switches between inputting the control code to the first slave TAP controller from the outside and inputting the control code through the master TAP controller, on the basis of the shift mode signal.

Abstract: In a first embodiment a Test Access Port (TAP) of IEEE standard 1149.1 is allowed to commandeer control from a Wrapper Serial Port (WSP) of IEEE standard P1500 such that the P1500 architecture, normally controlled by the WSP, is rendered controllable by the TAP. In a second embodiment (1) the TAP and WSP based architectures are merged together such that the sharing of the previously described architectural elements are possible, and (2) the TAP and WSP test interfaces are merged into a single optimized test interface that is operable to perform all operations of each separate test interface. One approach provides for the TAP to maintain access and control of the TAP instruction register, but provides for a selected data register to be accessed and controlled by either the TAP+ATC (Auxiliary Test Control bus) or by the discrete CaptureDR, UpdateDR, TransferDR, ShiftDR, and ClockDR WSP data register control signals.

Abstract: A method and circuits for implementing aperture function calibration for Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. The aperture function calibration uses aperture calibration data, and an LBIST calibration channel having a predefined number of scan inversions between the aperture calibration data and a multiple input signature register (MISR). LBIST is run selecting the LBIST calibration channel and masking other LBIST channels to the MISR. A change in the MISR value, for example, from zero to a non-zero value, is identified and an aperture adjustment is calculated and used to identify any needed adjustment of aperture edges.

Abstract: A test architecture accesses IP core test wrappers within an IC using a Link Instruction Register (LIR). An IEEE P1500 standard is in development for providing test access to these individual cores via a test structure called a wrapper. The wrapper resides at the boundary of the core and provides a way to test the core and the interconnections between cores. The test architecture enables each of the plural wrappers in the IC, including wrappers in cores embedded within other cores, with separate enable signals.

Abstract: A TAP linking module (21, 51) permits plural TAPs (TAPs 1-4) to be controlled and accessed from a test bus (13) via a single TAP interface (20).

Abstract: A semiconductor die includes interface logic for performing a function on an external device, and a surrogate circuit in communication with the interface logic. The interface logic facilitates testing of the interface logic by attempting to perform the function on the surrogate circuit. The interface logic may be a memory interface, and the surrogate circuit may be a memory circuit that is a smaller and simpler replica of an external memory die. The surrogate circuit allows the interface logic to be tested before the semiconductor die is physically coupled to the external device, for exampled in a three dimensional (3D) integrated circuit (IC).

Abstract: In a complex semiconductor device including embedded memories, the round trip latency may be determined during a memory self-test by applying a ping signal having the same latency as control and failure signals used during the self-test. The ping signal may be used for controlling an operation counter in order to obtain a reliable correspondence between the counter value and a memory operation causing a specified memory failure.

Abstract: A circuit includes an input node configured to receive a test address input signal and circuitry configured to generate, from a first part of the test address input signal, a first address signal that selects a first address of a first part of a circuit to be tested and further generate, from a second part of the test address input signal, a second signal configured to select a second part of the circuit to be tested. Test circuitry is then configured to use the first address and the second part in a test mode.