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: Aspects of the invention relate to techniques of using two-dimensional scan architecture for testing and diagnosis. A two-dimensional scan cell network may be constructed by coupling input for each scan cell to outputs for two or more other scan cells and/or primary inputs through a multiplexer. To test and diagnose the two-dimensional scan cell network, the two-dimensional scan cell network may be loaded with chain patterns and unloaded with corresponding chain test data along two or more sets of scan paths. Based on the chain test data, one or more defective scan cells or defective scan cell candidates may be determined.

Abstract: In a method for creating a clock domain in a layout of an integrated circuit, a test circuit of the integrated circuit includes a plurality of first scan cells and a plurality of second scan cells, the first scan cells are arranged to be on a first scan chain, and the second scan cells are arranged to be on a second scan chain. The method includes: for a first region in the layout, determining whether the first region needs a test clock domain adjustment according to densities of first scan cells and second scan cells within the first region; and when it is determined that the first region needs the test clock domain adjustment, arranging at least one first scan cell within the first region to be on the second scan chain.

Abstract: A semiconductor device includes a test pattern decoding unit and a scan chain unit. The test pattern receives a scan-in pattern from an external test device and generates a test pattern based on the scan-in pattern and a scan-out pattern. The scan-in pattern is decoded based on a seed pattern and an expectation pattern. The scan chain unit performs logical operation based on the test pattern and feedbacks the scan-out pattern to the test pattern decoding unit.

Abstract: A semiconductor integrated circuit has one or more of scan chains each having series-connected flip-flops that exist in an internal circuit. Each scan chain is divided into a plurality of segments. Each segment is controllable a timing of a clock signal. The semiconductor integrated circuit has a clock gating circuit capable of being shared by the scan chains and configured to generate a plurality of clock signals for driving each segment, the clock gating circuit being provided for each scan chain, and a segment control signal generator configured to generate a control signal to be used when the clock gating circuit generates the clock signals so that an effect of a fault of the internal circuit is transferred through one of the segments and care bits corresponding to a next fault are captured in a corresponding segment.

Abstract: The present disclosure describes using the JTAG Tap's TMS and/or TCK terminals as general purpose serial Input/Output (I/O) Manchester coded communication terminals. The Tap's TMS and/or TCK terminal can be used as a serial I/O communication channel between; (1) an IC and an external controller, (2) between a first and second IC, or (3) between a first and second core circuit within an IC. The use of the TMS and/or TCK terminal as serial I/O channels, as described, does not effect the standardized operation of the JTAG Tap, since the TMS and/or TCK I/O operations occur while the Tap is placed in a non-active steady state.

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: A multi-die chip module (MCM) comprises a first die containing a first test controller and a second die containing a second test controller coupled to the first die via an interconnect. The first test controller is configured to place the first die in either a shift mode or a capture mode. The second controller is configured to place the second die in either the shift mode or the capture mode. After a scan shift operation, scan cells are initialized to predetermined values. During the capture operation one die remains in the shift mode and the other die enters the capture mode so that as test bits are shifted into registers associated with output pads on the die in the shift mode, the other die is in the capture mode and captures signals on input pads associated with that die, enabling scan based at-speed testing of the interconnect.

Abstract: An integrated circuit can have plural core circuits, each having a test access port that is defined in IEEE standard 1149.1. Access to and control of these ports is though a test linking module. The test access ports on an integrated circuit can be arranged in a hierarchy with one test linking module controlling access to plural secondary test linking modules and test access ports. Each secondary test linking module in turn can also control access to tertiary test linking modules and test access ports. The test linking modules can also be used for emulation.

Abstract: Built-in self-test (BIST) microcontroller integrated circuit adapted for logic verification. Microcontroller includes a plurality of hardware description language files representing a hierarchical description of the microcontroller, the plurality of hardware description language files including a library of circuit design elements, a plurality of library design circuit elements adapted to store a uniquely defined set of input and output signals to enable a logic BIST, and a plurality of latches adapted to store a plurality of values corresponding to a behavioral profile of a test clock.

Abstract: The disclosure describes a novel method and apparatus for providing a shadow access port within a device. The shadow access port is accessed to perform operations in the device by reusing the TDI, TMS, TCK and TDO signals that are used to operate a test access port within the device. The presence and operation of the shadow access port is transparent to the presence and operation of the test access port. According to the disclosure, the shadow access port operates on the falling edge of the TCK signal while the test access port conventionally operates on the rising edge of the TCK signal.

Abstract: Embodiments of the disclosed technology comprise software-based techniques that can be used to improve scan chain test pattern generation and scan chain failure diagnosis resolution. For example, certain embodiments can be used to generate high quality chain diagnosis test patterns that are able to isolate a scan chain defect to a single scan cell. Such embodiments can be used to generate a “complete” test set—that is, a set of chain diagnosis test patterns that is able to isolate any scan chain defect in a faulty scan chain to a single scan cell.

Abstract: This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations.

Abstract: A scan test architecture facilitates low power testing of semiconductor circuits by selectively dividing the serial scan paths into shorter sections. Multiplexers between the sections control connecting the sections into longer or shorted paths. Select and enable signals control the operation of the scan path sections. The output of each scan path passes through a multiplexer to compare circuits on the semiconductor substrate. The compare circuits also receive expected data and mask data. The compare circuits provide a fail flag output from the semiconductor substrate.

Abstract: An integrated circuit or circuit board includes functional circuitry and a scan path. The scan path includes a test data input lead, a test data output lead, a multiplexer, and scan cells. A dedicated scan cell has a functional data output separate from a test data output. Shared scan cells each have a combined output for functional data and test data. The shared scan cells are coupled in series. The test data input of the first shared scan cell is connected to the test data output of the dedicated scan cell. The combined output of one shared scan cell is coupled to the test data input lead of another shared scan cell. The multiplexer has an input coupled to the test data output, an input connected to the combined output lead of the last shared scan cell in the series, and an output connected in the scan path.

Abstract: Aspects of the invention relate to techniques for diagnosing compound hold-time faults. A profiling-based scan chain diagnosis may be performed on a faulty scan chain to determine observed scan cell failing probability information and one or more faulty segments based on scan pattern test information. Calculated scan cell failing probability information may then be derived. Based on the calculated scan cell failing probability information and the observed scan cell failing probability information, one or more validated faulty segments are verified to have one or more compound hold-time faults. Finally, one or more clock defect suspects may be identified based on information of the one or more validated faulty segments.

Abstract: An interface device is adapted to: in a first mode, in reaction to test signals and corresponding to a test standard, output signals corresponding to the test standard via at least one signal line. In a second mode it is adapted to, in reaction to test signals and corresponding to the test standard, output signals that do not correspond to the test standard via the at least one signal line.

Abstract: Built-in self-test techniques for integrated circuits that address the issue of unknown states. Some implementations use a specialized scan chain selector coupled to a time compactor. The presence of the specialized scan chain selector increases the efficiency in masking X states. Also disclosed are: (1) an architecture of a selector that works with multiple scan chains and time compactors, (2) a method for determining and encoding per cycle scan chain selection masks used subsequently to suppress X states, and (3) a method to handle an over-masking phenomenon.

Abstract: The disclosure describes a novel method and apparatus for improving interposers that connected stacked die assemblies to system substrates. The improvement includes the addition of IEEE 1149.1 circuitry within interposers to allow simplifying interconnect testing of digital and analog signal connections between the interposer and system substrate it is attached too. The improvement also includes the additional 1149.1 controlled circuitry that allows real time monitoring of voltage supply and ground buses in the interposer. The improvement also includes the additional of 1149.1 controlled circuitry that allows real time monitoring of functional digital and analog input and output signals in the interposer. The improvement also provides the ability to selectively serially link the 1149.1 circuitry in the interposer with 1149.1 circuitry in the die of the stack.

Abstract: Scan and Scan-BIST architectures are commonly used to test digital circuitry in integrated circuits. The present disclosure improves upon low power Scan and Scan-BIST methods. The improvement allows the low power Scan and Scan-BIST architectures to achieve a delay test capability equally as effective as the delay test capabilities used in conventional scan and Scan-BIST architectures.

Abstract: An address and command port interface selectively enables JTAG TAP domain operations and Trace domain operations within an IC. The port carries TMS and TDI input and TDO output on a single pin and receives a clock signal on a separate pin. The addressable two pin interface loads and updates instructions and data to the TAP domain within the IC. The instruction or data update operations in multiple ICs occur simultaneously. A process transmits data from an addressed target device to a controller using data frames, each data frame comprising a header bit and data bits. The logic level of the header bit is used to start, continue, and stop the data transmission to the controller. A data and clock signal interface between a controller and multiple target devices provides for each target device to be individually addressed and commanded to perform a JTAG or Trace operation.

Abstract: Scan distributor, collector, and controller circuitry connect to the functional inputs and outputs of core circuitry on integrated circuits to provide testing through those functional inputs and outputs. Multiplexer and demultiplexer circuits select between the scan circuitry and the functional inputs and outputs. The core circuitry can also be provided with built-in scan distributor, collector, and controller circuitry to avoid having to add it external of the core circuitry. With appropriately placed built-in scan distributor and collector circuits, connecting together the functional inputs and outputs of the core circuitry also connects together the scan distributor and collector circuitry in each core. This can provide a hierarchy of scan circuitry and reduce the need for separate test interconnects and multiplexers.

Abstract: The present disclosure describes novel methods and apparatuses for directly accessing JTAG Tap domains that exist in a scan path of many serially connected JTAG Tap domains. Direct scan access to a selected Tap domain by a JTAG controller is achieved using auxiliary digital or analog terminals associated with the Tap domain and connected to the JTAG controller. During direct scan access, the auxiliary digital or analog terminals serve as serial data input and serial data output paths between the selected Tap domain and the JTAG controller.

Abstract: The disclosure provides a novel method and apparatus for inputting addresses to devices to select the device TAP for access. Further, the disclosure provides a novel method and apparatus for inputting addresses for selecting device TAPs and for inputting commands for commanding circuitry within the device. The inputting of addresses or the inputting of addresses and commands is initiated by a control bit input on TDI that is recognized during the Run Test/Idle, Pause-DR or Pause-IR TAP states.

Abstract: Today many instances of IEEE 1149.1 Tap domains are included in integrated circuits (ICs). While all TAP domains may be serially connected on a scan path that is accessible external to the IC, it is generally preferred to have selectivity on which Tap domain or Tap domains are accessed. Therefore Tap domain selection circuitry may be included in ICs and placed in the scan path along with the Tap domains. Ideally, the Tap domain selection circuitry should only be present in the scan path when it is necessary to modify which Tap domains are selected in the scan path. The present disclosure describes a novel method and apparatus which allows the Tap domain selection circuitry to be removed from the scan path after it has been used to select Tap domains and to be replaced back into the scan path when it is necessary to select different Tap domains.

Abstract: A scannable register array structure includes a plurality of individual latches, each configured to hold one bit of array data in a normal mode of operation. The plurality of individual latches operate in scannable latch pairs in a test mode of operation, with first latches of the scannable latch pairs comprising L1 latches and second latches of the scannable latch pairs comprising L2 latches. A test clock signal generates a first clock pulse signal, A, for the L1 latches and a second clock pulse signal, B, for the L2 latches. The L2 latches are further configured to selectively receive L1 data therein upon a separate activation of the B clock signal, independent of the test clock signal, such that a scan out operation of the individual latches results in observation of L1 latch data.

Abstract: A method for performing robust scan synthesis for soft-error protection on a design for generating a robust scan design in a system is modeled selectively at a register-transfer level (RTL) or a gate level; the design includes at least a sequential element or a scan cell for mapping to a robust scan cell of a select robust scan cell type. The method comprises performing a scan replacement and a scan stitching on the design database based on a given control information file for synthesizing the robust scan cell on the design database; and generating the synthesized robust scan design at a pre-determined RTL or a pre-determined gate level.

Abstract: A scan cell includes first, second and third data inputs and a control input. The first, second and third data inputs are configured to receive respective first, second and third data bits. The control input is configured to receive a control signal. Latching logic is configured to latch an input value to a scan cell output. Selection logic is configured to select the input value from between the first, second and third data bits, depending on a state of the control signal.

Abstract: An embodiment is directed to extended test coverage of complex multi-clock-domain integrated circuits without forgoing a structured and repeatable standard approach, thus avoiding custom solutions and freeing the designer to implement his RTL code, respecting only generally few mandatory rules identified by the DFT engineer. Such an embodiment is achieved by introducing in the test circuit an embodiment of an additional functional logic circuit block, named “inter-domain on chip clock controller” (icOCC), interfaced with every suitably adapted clock-gating circuit (OCC), of the different clock domains. The icOCC actuates synchronization among the different OCCs that source the test clock signals coming from an external ATE or ATPG tool and from internal at-speed test clock generators to the respective circuitries of the distinct clock domains. Scan structures like the OCCs, scan chain, etc., may be instantiated at gate pre-scan level, with low impact onto the functional RTL code written by the designer.

Abstract: A method, a system, and a processor for loading a logical device online are disclosed. The method for loading a logical device online includes receiving an online loading command; disabling a Joint Test Action Group (JTAG) link of a board on which the logical device is located through a bus between a processor and the logical device according to the online loading command, and enabling a link between an input/output (I/O) interface and a JTAG interface of the logical device through the bus according to the online loading command; and controlling the logical device through the bus so that the logical device is loaded online through the link between the I/O interface and the JTAG interface of the logical device. In this way, the logical device is loaded online without occupying any I/O interface or requiring addition of any I/O device.

Abstract: A scan cell is configured to receive first, second and third data bits at respective first, second and third data inputs. A control input is configured to receive a control signal. Latching logic is configured to latch data received at the first and second latch inputs to a scan cell output. The first latch input is configured to receive the first data bit. Selection logic is configured to select between the second and third data bits depending on a state of the control signal, and to provide the selected bit to the second latch input.

Abstract: A method for providing ordered capture clocks to detect or locate faults within N clock domains and faults crossing any two clock domains in an integrated circuit or circuit assembly in scan-test or self-test mode, where N>1, includes the steps of: (a) generating and shifting-in N test stimuli to all scan cells within the N clock domains during a shift-in operation; (b) applying an ordered sequence of capture clocks to all scan cells within the N clock domains, the ordered sequence of capture clocks including a plurality of capture clock pulses from two or more selected capture clocks placed in a sequential order such that all clock domains are never triggered simultaneously during a capture operation; and (c) analyzing output responses of all scan cells to locate any faults therein.

Abstract: An integrated circuit (IC) is provided. The IC includes a scan controller and a target logic circuit configured to receive a scan input pattern in response to a control of the scan controller, to execute an operation according to the scan input pattern, and to output an execution result. The scan controller compares the execution result with a scan output pattern and outputs a comparison result. The IC can perform a scan test on a particular block that is not controlled by a CPU in a smart card without an additional pad.

Abstract: A test structure for an integrated circuit device includes one or more experiments selectively configured to receive one or more high-speed input signals as inputs thereto and to output at least one high-speed output signal therefrom, the one or more experiments each including two or more logic gates configured to determine differential delay characteristics of individual circuit devices, at a precision level on the order of picoseconds to less than 1 picosecond; and wherein the one or more sets of experiments are disposed, and are fully testable, at a first level of metal wiring (Ml) in the integrated circuit device.

Abstract: A first circuit has a reset input. A second circuit is configured to be reset and provide an output. A test circuit is configured to test the first circuit and second circuit. The test circuit is configured such that a fault with the first circuit and said second circuit is determined in dependence on an output of the first circuit.

Abstract: In a test data access system, a shift register is coupled the test data in pin. A first multiplexer is in data communication with the TDI pin and is configured to receive data from the TDI pin and to transmit data to each of the instruments. The first multiplexer is also configured to receive data from a data recirculation bit and to transmit data from the TDI pin to a plurality of instruments when the recirculation bit has a first value and to transmit data to the plurality of instruments from a recirculation line when the recirculation bit has a second value, different from the first value. A second multiplexer is configured to receive data from each of the plurality of instruments and is configured to transmit data from a selected one of the plurality of instruments, selected based on a value of data in the shift register. A first AND gate is configured to generate a gates clock to the shift register. A second AND gate is responsive to the first AND gate, configured to lock the shift register.

Abstract: In a first embodiment a TAP of IEEE standard 1149.1 is allowed to commandeer control from a 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 or by the discrete CaptureDR, UpdateDR, TransferDR, ShiftDR, and ClockDR WSP data register control signals.

Abstract: Techniques are disclosed relating to testing logic in integrated circuits using an external test tool. In one embodiment, an integrated circuit includes a logic unit and a self-test unit. The self-test unit is configured to receive an expected signature value that corresponds to an expected output value of the logic unit, and to compare the expected signature value and an actual signature value generated from an actual output value from the logic unit. In some embodiments, the integrated circuit further includes a pseudo-random pattern generator configured to provide an input value to the logic unit, and the logic unit is configured to generate the actual output value based on the provided input value. In some embodiments, the integrated circuit further includes a multiple-input signature register (MISR) configured to generate the actual signature value based on the actual output value and a seed value.

Abstract: Methods and apparatus are provided related to testing electrical connectivity. A sequence of distinct test data signal patterns is issued. The test data signals are propagated by way of respective pathways and electrical connectors. A feedback signal is generated in accordance with a test function for each of the test data signal patterns. A test results message is generated in accordance with the feedback signals, which can include specific diagnostic or identifying information.

Abstract: A system for testing or debugging a device under test having an embedded logic analyzer. In one embodiment, the system includes software stored in non-transitory memory for testing a device under test having an embedded logic analyzer, the software program product having instructions which, when executed by a computing device associated with the device under test cause the computing device to reconstruct signals of interest in the device under test based at least in part upon signals captured by the embedded logic analyzer during the test or debug session, and cause the computing device to display the reconstructed signals of interest to a user of the computing device.

Abstract: This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations. In a fifth aspect of the present disclosure, an interface select circuit, FIGS. 41-49, provides for selectively using either the 5 signal interface of FIG. 41 or the 3 signal interface of FIG. 8.

Abstract: An IC includes an IEEE 1149.1 standard test access port (TAP) interface and an additional Off-Chip TAP interface. The Off-Chip TAP interface connects to the TAP of another IC. The Off Chip TAP interface can be selected by a TAP Linking Module on the IC.

Abstract: A system for scan testing an IC includes one or more scan registers, one or more scan-in pads, one or more scan-out pads, and one or more comparators. Scan test data is transmitted from the scan-in pads to the scan registers. The functional response obtained from the scan test is transmitted to the comparator. The scan-out pad transmits the expected data to the comparator. The comparator compares the expected data and the functional response data and the comparison result is stored. The test result data is transmitted at positive and negative edges of the test clock signal.

Abstract: A position-based scheduling capability supports interaction between one or more user applications and a scheduler for performing testing via a scan chain of a unit under test. The scheduler receives access requests from one or more user applications, where each access request is a request for access to a segment of the scan chain, respectively. The scheduler determines scheduling of the access requests using a circuit model configured to represent an ordering of the segments of the scan chain. The scheduler may provide the access responses to the user application(s) from which the access requests are received, thereby enabling the user application(s) to issue test operations toward a processor configured to generate test data to be applied to the scan chain. The scheduler may obtain the test operations and send the test operations toward a processor configured to generate test data to be applied to the scan chain.

Abstract: A system for correcting programming failures in an M-bit primary array of programmable fuses. The address of the failed fuse is stored in a secondary fuse array. Correction logic coupled to the primary and secondary arrays propagates the programming states of the good fuses, and corrects the programming state of the failed fuse, if any. The correction logic preferably comprises a decoder coupled to the secondary array which produces a one-hot M-bit word representing the failed fuse, and combinatorial logic arranged to receive the programming states of the primary array fuses and the one-hot M-bit word at respective inputs and to produce the correction logic output. Multiple failures can be accommodated using multiple secondary arrays, each storing the address of a respective failed fuse, or a tertiary array which stores the address of a failed fuse in either the primary or secondary arrays.

Abstract: A system and method for sharing a communications link between multiple protocols is described. A system includes a communications interface configured to exchange information with other systems using at least one of a plurality of protocols; a protocol select register that stores a value that selects a protocol from among the plurality of protocols to become an active protocol; and a state machine accessible to the communications interface, the state machine used to control the exchange of information through the communications interface according to the active protocol. The active protocol is used by the communications interface to exchange information while the remaining protocols of the plurality of protocols remain inactive. The state machine sequences through a series of states that cause the communications interface to operate according to the active protocol, and that are designated as inert sequences under the remaining protocols.

Abstract: In one embodiment, the present invention is directed to a logic analyzer such as may be implemented on a system-on-chip or another semiconductor device. The analyzer can include multiple lanes each having a filter to receive and filter debug data, a compressor to compress the debug data passed by the filter, a buffer, and a controller to store the compressed debug data into the buffer, where the compressed debug data can be stored without timing information. Other embodiments are described and claimed.

Abstract: A multi-chip test system and a method thereof utilize a Complex Programmable Logic Device (CPLD) to be connected in series to multiple chips having a Joint Test Action Group (JTAG) interface for function inspection. The test system includes a device to-be-tested and a control device. The device to-be-tested includes multiple chips, a CPLD, and a second JTAG interface. Each of the chips has a first JTAG interface. The CPLD is coupled to the chips through the first JTAG interfaces. The second JTAG interface is connected to the CPLD. The control device is connected to the second JTAG interface and used for sending a switching instruction to the CPLD. In the test method, firstly, a switching instruction is received to select a chip to-be-tested; then, a test signal is sent to the chip to-be-tested according to the chip to-be-tested; and the chip to-be-tested transfers a test result back to a CPLD according to the test signal.

Abstract: A method and apparatus to improve the efficiency of debugging a processor is provided. Also provided is a computer readable storage device encoded with data for adapting a manufacturing facility to create an apparatus. The method includes executing a first test pattern from a plurality of test patterns of a logic built-in self test (LBIST). The method further includes generating a first value based on the first test pattern. The method also further includes comparing the first value to a second value, and terminating the LBIST in response to determining that the first value does not equal the second value.

Abstract: An IC having a scan chain and a testing method for a chip, comprising a first interface group, a second interface group and a scan data selector. The first interface group and the second interface group each comprise at least two input/output (I/O) interfaces which can be packaged as external pins of the IC. The I/O interfaces of the first interface group are connected to input terminals of the scan data selector in one-to-one correspondence, and an output terminal of the scan data selector is connected to a scan data input terminal of the scan chain. A scan data output terminal of the scan chain is connected to the I/O interfaces of the second interface group.