Abstract: 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.

Abstract: A processing unit can include a performance monitor for monitoring the performance of the processing unit and associated sub-units. The performance monitor includes a logic analyzer, and implements a state machine via state machine data entries stored in a memory associated with the performance monitor. A state machine data entry includes output signals associated with state transitions. The output signals include a next state and a trigger to the logic analyzer. The performance monitor implements logic circuits that determine, based on input signals and the state machine data entries, the next state to transition and associated output signals. If a state transition includes a trigger to the logic analyzer, the trigger is transmitted to the logic analyzer. In response to the trigger, the logic analyzer assembles and samples input signals and stores the sampled input signals into the memory associated with the performance monitor, overwriting the state machine data entries.

Abstract: Herein are techniques that train regressor(s) to predict how effective would a machine learning model (MLM) be if trained with new hyperparameters and/or dataset. In an embodiment, for each training dataset, a computer derives, from the dataset, values for dataset metafeatures. The computer performs, for each hyperparameters configuration (HC) of a MLM, including landmark HCs: configuring the MLM based on the HC, training the MLM based on the dataset, and obtaining an empirical quality score that indicates how effective was said training the MLM when configured with the HC. A performance tuple is generated that contains: the HC, the values for the dataset metafeatures, the empirical quality score and, for each landmark configuration, the empirical quality score of the landmark configuration and/or the landmark configuration itself. Based on the performance tuples, a regressor is trained to predict an estimated quality score based on a given dataset and a given HC.

Abstract: A system includes a ring oscillator including an odd number of inverters arranged in a ring. The system also includes a time to digital converter including an odd number of flops, where each of the flops is coupled to an output of a different inverter. The system includes a level shifter coupled to the inverters and to the flops. The system also includes a Gray counter coupled to at least one of the flops. The system includes a decoder coupled to the time to digital converter. The system also includes a phase frequency detector coupled to the decoder.

Abstract: An integrated circuit device includes a plurality of cells or modules. Each respective one of the cells or modules consumes leakage power, and the amount of leakage power consumed by a respective one of the cells or modules varies depending on states of its inputs. Scan-chain circuitry is configured to propagate through the integrated circuit device, on entry of the integrated circuit device to a low-power mode, a scan-chain pattern created in advance, to apply, to each respective cell or module in the low-power mode, a set of inputs that results in a respective low-power state with reduced leakage power. Creating the scan chain pattern includes identifying respective ones of the cells or modules as having the highest leakage power consumption, and a respective combination of inputs to place each of those the cells or modules in a respective low-power state.

Abstract: A system includes a test access port (TAP) configured to provide internal joint test action group (IJTAG) access to one or more test data registry (TDR). The system further includes a plurality of hierarchical electronic components, wherein each hierarchical electronic component includes a de-asserted segment inserted bit (D-SIB) register, an asserted segment inserted bit (A-SIB) register, and a TDR associated with the D-SIB register. Each D-SIB register is configured to prevent access to its associated TDR when a reset signal is asserted and each A-SIB register is configured to provide access to its subsequent A-SIB register or D-SIB register coupled thereto when the reset signal is asserted.

Abstract: Disclosed is a transceiver which includes a logic circuit that generates parallel transmission data in response to a first test mode signal or a second test mode signal, a serializer that converts the parallel transmission data into serial transmission data, a driver that outputs the serial transmission data through transmission pads, an analog circuit that receives serial reception data through reception pads, a deserializer that converts the serial reception data into parallel reception data, a plurality of test switches switched in response to the first test mode signal, and a test circuit that is electrically connected to the analog circuit through the plurality of test switches and outputs serial post data corresponding to the serial transmission data to the analog circuit.

Abstract: A method is provided in the present disclosure. The method includes several operations: generating, by a processing unit, a mapping table associated with multiple scan chains and multiple shift cycles corresponding to multiple values stored in the scan chains in an integrated circuit; determining, based on the mapping table, at least one fail flip flop in the scan chains in response to the values outputted from the scan chains; and identifying at least one fault site corresponding to the at least one fail flip flop.

Abstract: Systems and methods disclosed include receiving defect data from a test of a semiconductor device comprising a circuit, the circuit comprising a cell, the cell comprising a first input, a second input and an output, and modeling a first plurality of cell defect modes of the cell with a first multiple input transition cell fault model (MTCFM), the cell defect modes associated with a first signal transition on the first input, and a second signal transition on the second input or the output. Systems and method further include correlating the first plurality of cell defect modes to the defect data to produce a probability of each of the first plurality of cell defect modes matching the defect data, and providing, to a user, an indication of each of at least one of the first plurality of cell defect modes having the probability exceeding a defect probability threshold.

Abstract: A data labeling method, apparatus and system are provided. The method includes: sampling a data source according to an evaluation task for the data source to obtain sampled data; generating a labeling task from the sampled data; sending the labeling task to a labeling device; and receiving a labeled result of the labeling task from the labeling device. As such, an automatic evaluation of data can be implemented by using the evaluation task, and evaluation efficiency is improved.

Abstract: A fault rules engine generates a plurality of fault rules files, each of the fault rules files is associated with a respective cell type of a plurality of cell types in an integrated circuit (IC) design. Each fault rules file includes data quantifying a nominal delay for a given two-cycle test pattern and data quantifying a delta delay for the given two-cycle test pattern corresponding to a given candidate defect of a plurality of candidate defects of a given cell type of the plurality of cell types in the IC design. An IC test engine extracts an input to output propagation delay for each cell instance from a standard delay format (SDF) file for the IC design and generates cell-aware test patterns for each cell instance of each cell type in the IC design based on the plurality of fault rules files and the extracted input to output propagation delays.

Abstract: Disclosed are a circuit unit, a circuit module and an apparatus for data statistics. The circuit unit comprises a first register and a second register, and stores data received via a first input terminal in the first register in a case where a first control terminal receives a valid control signal, stores data received via a second input terminal in the second register in a case where a second control terminal receives a valid control signal, and increases the value of data stored in the second register by 1 in a case where a third control terminal receives a valid control signal. The circuit module comprises one or more such circuit units, and the apparatus comprises one or more such circuit modules. The circuit module or the apparatus may use smaller resource and smaller power consumption to complete data statistics.

Abstract: An integrated circuit comprises scan test circuitry, additional circuitry subject to testing utilizing the scan test circuitry, and control circuitry associated with the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells, and the associated control circuitry is coupled to at least a given one of a primary input of the integrated circuit and a primary output of the integrated circuit. The scan test circuitry is configurable by the control circuitry so as to permit testing of both an input functional path associated with the given one of the primary input and the primary output and an output functional path associated with the given one of the primary input and the primary output.

Abstract: A combo dynamic flop with scan flop circuit includes a flip-flop circuit, a scan control circuit, and an output buffer circuit. The flip-flop circuit includes a dynamic latch circuit and a static latch circuit. The dynamic latch circuit includes a dynamic latch storage node. The static latch circuit includes a static storage node driven by the dynamic latch. The scan control circuit includes a scan slave feed-forward circuit, a scan latch circuit, and a scan driver circuit driven by the scan feed-back circuit. The scan latch circuit includes a scan feed-back circuit, a scan storage node, and a scan feed-forward circuit driven from the static latch. The output buffer circuit includes a dynamic latch driver driven from the dynamic latch circuit and a static driver driven from the static latch circuit.

Abstract: A scan flip-flop circuit comprises a scan input sub-circuit and a selection sub-circuit. The scan input sub-circuit is configured to receive a scan input signal and a scan enable signal and, when the scan enable signal is activated, generate complementary scan input signals representing the scan input signal that are delayed relative to a transition of a clock input signal between two different logic levels. The selection sub-circuit is coupled to the scan input sub-circuit and configured to receive the complementary scan input signals and, based on the scan enable signal, output an inverted version of either the scan input signal or a data signal as a first selected input signal.

Abstract: Each register in each built-in self-test (BIST) controller contains a BIST controller-specific start count value that is different from at least one other BIST controller-specific start count. A test controller provides a start command simultaneously to all the BIST controllers. This causes each of the BIST controllers to simultaneously begin a countdown of the BIST controller-specific start count values, using a counter. Each of the BIST controllers starts a test procedure in a corresponding BIST domain when the countdown completes (in the corresponding BIST controller). Thus, the test procedure starts at different times in at least two of the BIST domains based on the difference of the BIST controller-specific start count values in the different registers. Further, during the test procedure, each stagger controller can stagger the start of each BIST engine within the corresponding BIST domain to which the stagger controller is connected.

Abstract: Systems and methods for latches are presented. In one embodiment a system includes scan in propagation component, data propagation component, and control component. The scan in propagation component is operable to select between a scan in value and a recirculation value. The data propagation component is operable to select between a data value and results forwarded from the scan in propagation component, wherein results of the data propagation component are forwarded as the recirculation value to the scan in propagation component. The control component is operable to control an indication of a selection by the scan in propagation component and the data propagation component.

Abstract: A test architecture for 3D ICs is provided in which Through-Silicon-Vias and die logic can be tested pre-bonding dies in the stack for the 3D ICs. Post-bond scan test architecture is reconfigured to be accessed during pre-bond testing through using stratigically placed MUXs and TSVs. By connecting post-bond architecture including scan flops and boundary registers to gated scan flops used in TSV testing, an internal chain of scan flops such as typically used in post-bond testing can be selectively connected to gated scan flops connected to one end of each TSV for pre-bond testing of the internal logic through the TSVs.

Abstract: The invention provides a boundary scan test interface circuit. The boundary scan test interface circuit includes N test input pads, a test interfacing module and M test output pads, wherein N and M are positive integers, and M is smaller than N. The test interfacing module is coupled to the test input pads. The test interfacing module having a plurality of logical gates, and each of input pins of each of the logical gates coupled to each of the test input pads. The test output pads are coupled to output pins of the logical gates in the test interfacing module.

Abstract: A processor includes a TCU TAP for access of a TCU for running functional tests and a DAP TAP for access of a debugger. A TAP selection module selects reversibly TAP access by default through the TCU TAP when the processor is a bare die, or by default through the DAP TAP when the processor is packaged, the selection of TAP access being reversible by the TCU. The processor also includes a fuse for irreversibly disabling the selection by the TAP selection module of the TAP access by default through the TCU TAP. Functional tests on bare dies are run with a TCU probing the dies through the TCU TAP by default. Packaged engineering samples can be supplied for debugging with the DAP TAP selected by default, but access possible for the TCU through the TCU TAP.

Abstract: Circuits and methods are provided for debugging an integrated circuit. An integrated circuit includes core circuitry, scan test circuitry, scan control circuitry, and debug control circuitry. The scan test circuitry includes scan chains with scan cells interspersed throughout the core circuitry. The scan control circuitry controls the scan test circuitry to scan test the core circuitry. The debug control circuitry utilizes the scan test circuitry and controls the scan control circuitry to debug failure conditions of the integrated circuit during normal use. The scan control circuitry applies a debug clock signal to a clock port of each scan cell of a given scan chain to store data values that are generated by the core circuitry into the scan cells. The scan control circuitry controls the scan test circuitry to scan shift out the stored data values generated by the core circuitry during the debug process.

Abstract: An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells. The integrated circuit further comprises a clock distribution network configured to provide clock signals to respective portions of the integrated circuit. The clock distribution network comprises a clock tree having clock signal lines, and clock control elements arranged in respective selected ones of the clock signal lines of the clock tree, where the clock control elements are configured to separate at least one synchronous clock domain into multiple asynchronous clock domains during scan testing. The clock control elements may be configured to reduce a number of timing exceptions produced during scan testing relative to a number of timing exceptions that would otherwise be produced if scan testing were performed using the synchronous clock domain.

Abstract: A path-based crosstalk fault model is used in conjunction with a built-in self-test (BIST) and software capability for automatic test pattern generation. The solution allows for test patterns to be generated that maximize switching activity as well as inductive and capacitive crosstalk. The path based fault model targets the accumulative effect of crosstalk along a particular net (“victim” path), as compared with the discrete nets used in conventional fault models. The BIST solution allows for full controllability of the target paths and any associated aggressors. The BIST combined with automatic test pattern generation software enables defect detection and silicon validation of delay defects on long parallel nets.

Abstract: Techniques and mechanisms for evaluating I/O buffer circuits. In an embodiment, test rounds are performed for a device including the I/O buffer circuits, each of the test rounds comprising a respective loop-back test for each of the I/O buffer circuits. Each of the test rounds corresponds to a different respective delay between a transmit clock signal and a receive clock signal. In another embodiment, a first test round indicates a failure condition for at least one I/O buffer circuit and a second test round indicates the failure condition for each of the I/O buffer circuits. Evaluation of the I/O buffer circuits determines whether the device satisfies a test condition, where the determining is based on a difference between the delay corresponding to the first test round and the delay corresponding to the second test round.

Abstract: Systems and techniques for hot-plugging debugger capabilities are described. A described integrated circuit device includes a processor, a first pad interface, a detector configured to detect a clock signal via the first pad interface, one or more second pad interfaces, two or more components including a debug system that is communicatively coupled with the processor, a multiplexer communicatively coupled with the one or more second pad interfaces and the two or more components, and configured to selectively interconnect the one or more second pad interfaces with a selected component of the two or more components. The multiplexer can be configured to cause the debug system to be the selected component when the clock signal is detected via the first pad interface.

Abstract: A computer-implemented method for test case result processing includes receiving, by a test case result processing logic in a processor of a computer, a test result from a test case that executes on the computer; determining, by the test case result processing logic based on a result description file, whether a result description corresponding to the received result exists in the result description file; based on the result description corresponding to the received result existing in the result description file, determining an action description associated with the result description based on an action definition file; and executing an action corresponding to the determined action description.

Abstract: An integrated circuit includes an LBIST controller operative to run a test program on at least one selection of core logic of the integrated circuit to test the operability of the at least one selection of core logic. The integrated circuit also includes a monitoring logic structure operative to detect at least one type of operation executed for the test program from at least one particular control signal activated by the LBIST controller for controlling the at least one selection of core logic to execute the test program from among at least one control signal for controlling operations on the at least one selection of core logic.

Abstract: A system and method for efficiently debugging an integrated circuit with on-die hardware. A processor core includes an on-die debug state machine (DSM). The DSM includes multiple programmable storage elements for storing parameter values corresponding to multiple contexts. Each context is associated with a given one of multiple instruction sequences, such as at least threads and power-performance states. The DSM detects a sequence identifier (ID) and selects a context based on the sequence ID. The corresponding parameter values are used by transition conditions (triggers) and taken debug actions in a finite state machine (FSM) within the DSM. Each state and transition in the FSM is used by each one of the multiple contexts. The programmable DSM shares many resources, rather than replicating them, while being used for multiple sequences.

Abstract: A low power scan flip-flop cell includes a multiplexer, a master latch, a scan slave latch and a data slave latch. The master latch is connected to the multiplexer, and used for generating a first latch signal. The scan slave latch is connected to the master latch, and generates a scan output (SO) signal. The data slave latch is connected to the master latch, and generates a Q output depending on a scan enable (SE) input signal and the first latch signal. The Q output is maintained at a predetermined level during scan mode, which eliminates unnecessary switching of combinational logic connected to the scan flip-flop cell and thus reduces power consumption.

Abstract: An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having scan cells. The scan test circuitry is configured to control at least a given one of the scan cells so as to prevent the scan cell from capturing a potentially non-deterministic value from a portion of the additional circuitry. The portion of the additional circuitry that provides the potentially non-deterministic value may comprise, for example, at least one of a mixed signal logic block and a memory block of the additional circuitry. The given scan cell may be controlled by configuring the scan cell such that it is unable to capture data in a scan capture mode of operation in which it would otherwise normally be able to capture data.

Abstract: A system for performing a scan test on an integrated circuit such as a System on a Chip (SoC) that may be packaged in different package types and with different features enabled includes a bypass-signal generator and a first scan-bypass circuit. The bypass-signal generator generates a first bypass signal based on chip package information. The first bypass signal indicates whether a first scan chain associated with a first non-common circuit block of the SoC is to be bypassed. The first scan chain is bypassed in response to the first bypass signal. By enabling partial scan testing based on package information, unintentional yield loss caused by a full scan test determining an SoC is faulty can be avoided.

Abstract: A system for testing an error detection circuit includes a fault injection unit for operating the error detection circuit in a fault injection mode. A fault is inserted in either of a primary or a redundant processor. Output signals generated by the primary and redundant processors are compared and checked for a mismatch and the error detection circuit outputs a test signal based on the comparison result.

Abstract: Embodiments relate to systems and methods for defect detection and localization in semiconductor chips. In an embodiment, a plurality of registers is arranged in a semiconductor chip. The particular number of registers can vary according to a desired level of localization, and the plurality of registers are geometrically distributed such that defect detection and localization over the entire chip area or a desired chip area, such as a central active region, is achieved in embodiments. In operation, a defect detection and localization routine can be run in parallel with other normal chip functions during a power-up or other phase. In embodiments, the registers can be multi-functional in that they can be used for other operational functions of the chip when not used for defect detection and localization, and vice-versa. Embodiments thereby provide fast, localized defect detection.

Abstract: A method and apparatus for detecting clock glitches during at-speed testing of integrated circuits is disclosed. In one embodiment, an integrated circuit includes a scan chain having a number of scan elements coupled in a series configuration. Each of the scan elements is coupled to receive a clock signal that may be cycled during a test operation. A subset of the scan elements are arranged to form, along with other components, a counter. Test stimulus data shifted into the scan chain to perform a test may include an initial count value that is shifted into the scan elements of the counter. When the test is performed, the count value is updated responsive to cycling of the clock signal. The updated count value is shifted from the counter along with other test result data, and may be used to determine if the number of clock cycles received during the test.

Abstract: A method for detecting unstable signatures when testing a VLSI chip that includes adding to an LFSR one or more save and restore registers for storing an initial seed consisting of 0s and 1s; loading the initial seed into the one or more save and restoring LFSR registers upon reaching a predetermined number of test loops; performing a signature stability test by loading said initial seed to said LFSR, executing the predetermined number of BIST test loops, and comparing the resulting MISR signature for differences versus a previous signature stored in a MISR save and restore register.

Abstract: A method of sending programming and debug commands, comprises loading control instructions on a processor from an attached tangible, non-transitory computer-readable medium, copying the contents of a program image file by the processor from the computer-readable medium across a bus to a programmable device on the same card as the processor, signaling the programmable device to send an instruction to a configurable logic device (CLD) on the same card as the processor via a debug channel.

Abstract: Methods and apparatus for testing Input/Output (I/O) boundary scan chains for Systems on a Chip (SoCs) having I/Os that are powered off by default. Some methods and apparatus include implementation of boundary scan chain bypass routing schemes that selectively route a boundary scan chain path around I/O interfaces and/or ports that are powered off by default. Other techniques include selectively power-on I/Os that are powered off by default in a manner that is independent of SoC facilities for controlling the power state of the I/Os during SoC runtime operations. Various schemes facilitate boundary scan testing in accordance with IEEE Std.-1149.1 methodology.

Abstract: Techniques related to remotely boundary scanning of an integrated circuit embedded in a target computing system are disclosed herein. In an example, a host computing system includes a first peripheral port and a second peripheral port. A port-to-port boundary scan assembly is to interface boundary scan data between the first and the second peripheral ports. Thereby the boundary scan data can be routed from the second peripheral bus to the target computing system via a network port at the host computing system.

Abstract: An operating system independent JTAG debugging system implemented to run in a web browser. The software executing in the browser identifies the JTAG enabled components in the target system that is to be tested, and automatically downloads the latest versions of the appropriate software, JTAG drivers and configuration information from a test server.

Abstract: Embodiments of the invention are generally directed to systems, methods, and apparatuses for hybrid memory. In one embodiment, a hybrid memory may include a package substrate. The hybrid memory may also include a hybrid memory buffer chip attached to the first side of the package substrate. High speed input/output (HSIO) logic supporting a HSIO interface with a processor. The hybrid memory also includes packet processing logic to support a packet processing protocol on the HSIO interface. Additionally, the hybrid memory also has one or more memory tiles that are vertically stacked on the hybrid memory buffer.

Abstract: A method to perform component testing by supplying test patterns to a serial input pin coupled to an IEEE 1149.6 boundary-scan cell that is associated with an IEEE 1149.6 test receiver. The test receiver is configured to operate in a scan test mode. The output from the test receiver circuit is coupled to a logic block to be scan tested. The output from the logic block is coupled to a serial output pin on the integrated circuit during scan test mode. High performance integrated circuits can use SerDes pins in a scan test mode to be scan tested without impacting mission critical signals.

Abstract: An integrated circuit comprises a memory or other circuit core having an input interface and an output interface, scan circuitry comprising at least one scan chain having a plurality of scan cells, and additional circuitry associated with at least one of the input interface and the output interface and testable utilizing said at least one scan chain. The scan circuitry further comprises a scan controller configured to control signal values applied to one or more signal lines of the input interface in conjunction with testing of the additional circuitry utilizing said at least one scan chain. For example, the scan controller may control signal values applied to respective address input and write enable signal lines in a manner that ensures that data written to a memory in a write operation of a given memory cycle can be read from the memory in a read operation of a subsequent memory cycle.

Abstract: Various embodiments of methods and integrated circuits capable of generating a test mode control signal for a scan test through a scan chain (such as in an integrated circuit) are provided. The integrated circuit includes a test pattern detection block, a counter circuit, and a control circuit. The test pattern detection block is configured to receive a detection pattern and to detect a first pattern corresponding to a shift phase and a second pattern corresponding to a capture phase of a test pattern based on the detection pattern and to generate a trigger signal based upon the detection of the patterns. The control circuit generates and controls the test mode control signal based on the count states. The counter circuit is configured to generate one or more count states corresponding to one of the shift phase, the capture phase and the clock signal based on the detected pattern.

Abstract: An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having scan cells. The scan test circuitry further comprises transition launch mode selection circuitry configured to provide independent selection between multiple transition launch modes for each of a plurality of clock domains of the integrated circuit. The multiple transition launch modes may include, for example, at least a launch-on-shift mode and a launch-on-capture mode. These transition launch modes provide different manners of launching a given signal transition via at least one of the scan cells in a corresponding one of the clock domains. The transition launch mode selection circuitry may be configured to generate from a common shift enable signal multiple independently controllable shift enable signals for respective ones of the clock domains of the integrated circuit.

Abstract: An integrated circuit comprises a memory or other type of circuit core having an input interface and an output interface, built-in self-test circuitry configured for testing of the circuit core between its input and output interfaces in a built-in self-test mode of operation, and at least one scan chain having a plurality of scan cells. The scan cells of the scan chain are coupled to respective signal lines at the input and output interfaces and configured to allow capture of functional signal values from those signal lines in a functional mode of operation and shifting out of the captured functional signal values in a scan shift mode of operation. This allows detection of faults associated with functional paths of the interface that would otherwise not be detectable using the built-in self-test circuitry.

Abstract: Methods and structure for correlating multiple sets of test output signals in time are provided. The structure includes an integrated circuit comprising a block of circuitry that generates internal operational signals. The circuit also comprises a test multiplexer (MUX) hierarchy that selects subsets of the internal signals and applies the subsets to a testing element. A clock generator generates a clock signal for the selected signals. A test logic timer receives the clock signal and increments a counter value, and applies the counter value to the testing element. An event detector resets the counter value upon detection of an event, such that a first subset of the internal signals acquired from the test MUX hierarchy acquired responsive to detection of a first instance of the event may be correlated in time with a second subset of the internal signals acquired responsive to detection of a second instance of the event.

Abstract: Methods and structure for correlating internal operational signals routed via different paths of a test signal selection hierarchy. The structure includes a functional block of circuitry operable to generate internal operational signals and clock signals. The integrated circuit also comprises a test signal selection hierarchy operable to receive the internal operational signals and the clock signals and to selectively route the internal operational signals and the clock signals. Further, structure includes a control unit operable to receive the clock signals from the test signal selection hierarchy, to determine a delay between received clock signals routed via different signaling pathways of the test signal selection hierarchy. The control unit is further operable to program a delay line based upon the delay between the clock signals and based upon internal operational signals correlated with the clock signals.

Abstract: According to at least one exemplary embodiment, a synchronous active high reset scan flip flop is provided. The synchronous active high reset scan flip flop may include a data input, a serial input, a test enable input, a reset input, a clock input, a device output. It may also include an AND gate configured to receive the serial input and the test enable input and a multiplexer configured to receive the data input and a first output signal received from the AND gate. The multiplexer is operable in response to the reset input which is used to reset the flip flop in function mode, and permit scan test in test mode. The synchronous active high reset scan flip flop may also include a storage element configured to receive a second output signal received from the multiplexer and operable in response to a clock signal received from the clock input.

Abstract: An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells. The integrated circuit further comprises a clock distribution network configured to provide clock signals to respective portions of the integrated circuit. The clock distribution network comprises clock gating circuitry configured to control delivery of one or more of the clock signals along respective clock signal lines of the clock distribution network at least in part responsive to a scan shift control signal that is also utilized to cause the scan cells to form a serial shift register during scan testing. The clock gating circuitry may be used to determine whether a clock delay defect that causes a scan error during scan testing will also cause a functional error during functional operation, thereby improving yield in integrated circuit manufacturing.

Abstract: A scan circuit (JTAG 1149 extension) for a microprocessor utilizes transport logic and scan chains which operate at a faster clock speed than the external JTAG clock. The transport logic converts the input serial data stream (TDI) into input data packets which are sent to scan chains, and converts output data packets into an output data stream (TDO). The transport logic includes a deserializer having a sliced input buffer, and a serializer having a sliced output buffer. The scan circuit can be used for testing with boundary scan latches, or to control internal functions of the microprocessor. Local clock buffers can be used to distribute the clock signals, controlled by thold signals generated from oversampling of the external clock. The result is a JTAG scanning system which is not limited by the external JTAG clock speed, allowing multiple internal scan operations to complete within a single external JTAG cycle.