Abstract: In a first clock frequency multiplier, multiple injection-locked oscillators (ILOs) having spectrally-staggered lock ranges are operated in parallel to effect a collective input frequency range substantially wider than that of a solitary ILO. After each input frequency change, the ILO output clocks may be evaluated according to one or more qualifying criteria to select one of the ILOs as the final clock source. In a second clock frequency multiplier, a flexible-injection-rate injection-locked oscillator locks to super-harmonic, sub-harmonic or at-frequency injection pulses, seamlessly transitioning between the different injection pulse rates to enable a broad input frequency range. The frequency multiplication factor effected by the first and/or second clock frequency multipliers in response to an input clock is determined on the fly and then compared with a programmed (desired) multiplication factor to select between different frequency-divided instances of the frequency-multiplied clock.

Abstract: A method, system, and/or computer program product of scanning of an integrated circuit including chiplets to isolate fault locations is provided herein. The scanning of the integrated circuit includes providing, by a pervasive of the integrated circuit, an input to the chiplets. Each of the chiplets can include a pervasive satellite, a multiplexer, and latches. The scanning of the integrated circuit includes also scanning, by each pervasive satellite of the chiplets, data based on the input via the multiplexer into the latches to produce scan data for each of the chiplets. The scanning of the integrated circuit also includes comparing, by the pervasive of the integrated circuit, the scan data of each of the chiplets to expectant data stored on the pervasive to isolate the fault locations.

Abstract: Aspects of the invention relate to a test-per-clock scheme based on dynamically-partitioned reconfigurable scan chains. Every clock cycle, scan chains configured by a control signal to operate in a shifting-launching mode shift in test stimuli one bit and immediately applies the newly formed test pattern to the circuit-under-test; and scan chains configured by the control signal to operate in a capturing-compacting-shifting mode shift out one bit of previously compacted test response data while compacting remaining bits of the previously compacted test response data with a currently-captured test response to form currently compacted test response data. A large number of scan chains may be configured by the control signal to work in a mission mode. After a predetermined number of clock cycles, a different control signal may be applied to reconfigure and partition the scan chains for applying different test stimuli.

Abstract: A method for designing clock gates which may reduce timing requirements associated with clock gating control signals may include identifying a clock gating function included in a Hardware Description Language of an integrated circuit, wherein the clock gating function may include capturing a state of an enable signal dependent upon a clock signal. The method may include determining a delay time for capturing the state of the enable signal dependent on a time difference between transitions of the enable signal and the clock signal. The method may include creating a gating circuit, in which the gating circuit includes a delay unit coupled to a source of the clock signal, and wherein a delay value is dependent upon the amount of time to delay capturing the enable signal. The method may include modifying the HDL model dependent upon the clock gating circuit.

Abstract: In some embodiments, a flip-flop is laid-out on a flip-flop region of a semiconductor substrate. The flip-flop includes master switch circuitry made of a first plurality of devices which are circumscribed by a master switch perimeter residing within the flip-flop region. Scan mux input circuitry is operably coupled to an input of the master switch circuitry. The scan mux input circuitry is made up of a second plurality of devices that are circumscribed by a scan mux perimeter which resides within the flip-flop region and which is non-overlapping with the master switch perimeter. Slave switch circuitry is operably coupled to an output of the master switch circuitry. The slave switch circuitry is made up of a third plurality of devices that are circumscribed by a slave switch perimeter which resides within the flip-flop region and which is non-overlapping with both the master switch perimeter and the scan mux perimeter.

Abstract: There is set forth herein a semiconductor structure including a plurality of test devices, the plurality of test devices including a first test device and a second test device. A semiconductor structure can also include a waveform generating circuit, the waveform generating circuit configured for application of a first stress signal waveform having a first duty cycle to the first test device, and a second stress signal waveform having a second duty cycle to the second test device. A semiconductor structure can include a selection circuit associated with each of the first test device and the second test device for switching between a stress cycle and a sensing cycle.

Abstract: One or more systems and methods for scan cell assignment for a design layout of a semiconductor arrangement are provided. The design layout is evaluated to identify a set of sequential cells, such as flip flops connected to circuitry by data paths. Sequential cells within the set of sequential cells are assigned to either a scan cell assignment or a non-scan cell assignment based upon a control path criterion, a register bank criterion, a pipeline depth criterion, a sequential loop criterion, or other criteria to create a cell assignment list. Scan paths are connected to sequential cells assigned to the scan cell assignment so that test patterns can be sent to and received from such sequential cells during testing of the semiconductor arrangement for defects. Power, performance, and area utilization are improved because at least some sequential cells are assigned to the non-scan cell assignment.

Abstract: An input signal having at least one modulated signal is captured. At least four analog sample streams are generated from the input signal. Each analog sample stream is generated by sampling the input signal at a frequency substantially equal to the frequency at which each other analog sample stream is generated and at a phase separate from that at which each other analog sample stream is generated. For each analog sample stream, multiple analog samples of the analog sample stream are combined to create a bandwidth adjusted signal. The bandwidth adjusted signals are jointly representative of the input signal.

Abstract: Flip-flop cells that enable time borrowing during the design of the IC to improve setup times while avoiding introducing meta-stability, and alternatively to avoid hold time violations. The flip-flop cells are connected with logic cells in functional data paths. The flip-flop cell has a clock signal controlling both its input and output. A selective delay cell selectively delays either a data signal input to the flip-flop cell or the clock signal controlling the flip-flop cell. The selectively delayed signal adjusts the timing (setup, hold and clock-to-output) of the data path.

Abstract: A method and apparatus to deskew dead cycles is described using a block aligner. In one example a method includes receiving a sequence of bytes into a first buffer from each lane of a multiple lane peripheral device bus and receiving the sequence of bytes into a second buffer delayed one clock cycle from the first buffer. The method further includes providing the sequence of bytes from the first buffer to an output buffer, counting clock cycles of data as the data is received into the first and second buffers, upon reaching a predetermined count, inserting a dead cycle into the output buffer, and after inserting the dead cycle providing the sequence of bytes from the second buffer instead of the first buffer to the output buffer.

Abstract: Aspects of the invention relate to a test-per-clock scheme based on dynamically-partitioned reconfigurable scan chains. Every clock cycle, scan chains configured by a control signal to operate in a shifting-launching mode shift in test stimuli one bit and immediately applies the newly formed test pattern to the circuit-under-test; and scan chains configured by the control signal to operate in a capturing-compacting-shifting mode shift out one bit of previously compacted test response data while compacting remaining bits of the previously compacted test response data with a currently-captured test response to form currently compacted test response data. A large number of scan chains may be configured by the control signal to work in a mission mode. After a predetermined number of clock cycles, a different control signal may be applied to reconfigure and partition the scan chains for applying different test stimuli.

Abstract: We report methods relating to scan warmup of integrated circuit devices. One such method may comprise loading a scan test stimulus to and unloading a scan test response from a first set of logic elements of an integrated circuit device at a scan clock first frequency equal to a test clock frequency; adjusting the scan clock from the first frequency to a second frequency by a scan warmup unit, wherein the scan clock second frequency is equal to a system clock frequency; and capturing the scan test response by a shift logic at the scan clock second frequency. We also report processors containing components configured to implement the method, and fabrication of such processors. The methods and their implementation may reduce di/dt events otherwise commonly occurring when testing logic elements of integrated circuit devices.

Abstract: A semiconductor chip includes on-chip clock controllers (OCCs) capable of synchronizing multiple clock signals on the device. Each OCC controller receives a scan enable signal and a unique clock signal that is generated from one or more clock generators. The OCC receiving the slowest generated clock signal passes it through internal meta-stability registers and provides an external synchronization signal to the OCCs handling faster clock signals. These faster-clock OCCs can use the external synchronization signal to synchronize their clocks and generate testing clock pulses.

Abstract: An embodiment provides a circuit for testing an integrated circuit. The circuit includes a scan compression architecture driven by a scan clock and generates M scan outputs, where M is an integer. A clock divider is configured to divide the scan clock by k to generate k number of phase-shifted scan clocks, where k is an integer. A packing logic is coupled to the scan compression architecture and generates kM slow scan outputs in response to the M scan outputs and the k number of phase shifted scan clocks. The packing logic further includes M number of packing elements. Each packing element includes k number of flip-flops. Each flip-flop of the k number of flip-flops receives a scan output of the M scan outputs and a phase-shifted scan clock of the k number of phase-shifted scan clocks, and generates a slow scan output of the kM slow scan outputs.

Abstract: A Propagation Test instruction, a Decay Test instruction and a Cycle Test instruction provide testing of DC and AC interconnect circuits between circuits including JTAG boundary scan cells. A few additions to the Test Access Port circuitry, including gating producing a Capture Test Strobe (CTS) signal, and the boundary scan cells are required to implement the additional instructions. The instructions are extensions of the conventional JTAG operating structure.

Abstract: A method for testing an integrated circuit to reduce peak power problems during scan capture mode is presented. The method comprises programming a respective duration of a first time window for each of a plurality of cores and a cache on the integrated circuit. It further comprises counting the number of pulses of a first clock signal during the first time window for each of the plurality of cores and the cache. Subsequently, the method comprises staggering capture pulses to the plurality of cores and the cache by generating pulses of a second clock signal for each of the plurality of cores and the cache during a respective second time window, wherein the number of pulses generated is based on the respective number of first clock signal pulses counted for each of the plurality of cores and the cache.

Abstract: An on-chip clock controller includes a clock-control chain configured to shift first clock-control bits in serial and output the first clock-control bits to a first clock domain in parallel in response to a clock-control scan clock provided from outside of a chip, and a first domain clock generator, the first domain clock generator configured, during a test mode, to generate a first internal clock by selectively outputting a first data scan clock provided from outside of the chip or a first functional clock generated from inside of the chip.

Abstract: A circuit for a phase detector is provided. A first buffer of the circuit receives a data signal and generates a first modified data signal using the data signal. A notifier receives the data signal and determines whether a violation exists. A first multiplexer receives the first modified data signal and transmits a first multiplexer signal to a second multiplexer. The second multiplexer receives the first multiplexer data signal and the first modified data signal, and transmits a second multiplexer data signal to a flip-flop of the phase detector.

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: A method of operating an apparatus in a functional mode and an ATPG scan mode and an apparatus for use in a functional mode and an ATPG scan mode are provided. The apparatus includes a set of latches including a first latch and a second latch. The first latch is operated as a master latch and the second latch is operated as a master latch in the functional mode. The first latch is operated as a master latch of a flip-flop and the second latch is operated as a slave latch of the flip-flop in the ATPG scan mode. In one configuration, the apparatus includes a plurality of latches including at least the first and second latches, an output of each of the latches is coupled to a digital circuit, the apparatus includes a plurality of functional inputs, and each of the functional inputs is input to the digital circuit.

Abstract: A method and structure tests a system on a chip (SoC) or other integrated circuit having multiple cores for chip characterization to produce a partial good status. A Self Evaluation Engine (SEE) on each core creates a quality metric or partial good value for the core. The SEE executes one or more tests to create a characterization signature for the core. The SEE then compares the characterization signature of a core with a characterization signature of neighboring cores to determine the partial good value for the core. The SEE may output a result to create a full characterization map for detailed diagnostics or a partial good map with values for all cores to produce a partial good status for the entire SoC.

Abstract: An integrated circuit with toggle suppression logic for built-in self-test is provided. The integrated includes a loading circuit configured to operate in a shift mode based on a first enable signal and a capture mode based on a second enable signal. The integrated circuit includes a switching element configured to receive the first enable signal and the second enable signal to generate a third enable signal. The integrated circuit includes combinational logic coupled to the loading circuit and the switching element, in which the combinational logic is configured to receive the third enable signal. The third enable signal is configured to disable toggling in the combinational logic while the loading circuit operates in the shift mode.

Abstract: An isolation circuit includes a first multiplexer, a D flip-flop, a second multiplexer, an OR gate, and an AND gate. The first multiplexer selects a data signal or a scan-in signal as a first element output signal according to a scan enable signal. The D flip-flop generates a second element output signal according to the first element output signal. The second element output signal is fed back to the first multiplexer and is used as the data signal. The second multiplexer selects an isolation signal or the second element output signal as a third element output signal according to a test enable signal. The OR gate generates a fourth element output signal according to the scan enable signal and the third element output signal. The AND gate generates a second power domain signal according to a first power domain signal and the fourth element output signal.

Abstract: An integrated circuit chip includes a plurality of test input pads configured to receive a plurality of test input signals, a plurality of single-ended type buffers configured to receive signals input to the plurality of test input pads in a connectivity test mode, a plurality of differential-type buffers configured to receive signals input to the plurality of test input pads in a normal mode, a signal combination unit configured to combine the plurality of test input signals input through the plurality of single-ended type buffers, and to generate a plurality of test output signals, and a plurality of test output pads configured to output the plurality of test output signals in the connectivity test mode.

Abstract: Embodiments of the present invention provide a debugging method, a chip, a board, and a system and relate to the communications field. Remote debugging can be performed on a board having no main control CPU without affecting hardware distribution and software performance. The method includes: receiving, by an Ethernet port, a data packet and determining a current service type according to a service identifier carried in the data packet; when determining the current service type is a debugging service, writing the data packet into a memory through a bus and sending an interruption notification to a CPU through the bus; reading, by the CPU, the data packet from the memory according to the interruption notification, obtaining a debugging instruction by parsing the data packet, and sending the debugging instruction to an ASIC through a protocol conversion module.

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 multipoint low-voltage differential signaling (mLVDS)receiver of a semiconductor device and a buffering circuit of a semiconductor device, includes: an even-number data buffering unit configured to: sample even-number data from input data, amplify and output the even-number data in a section in which a positive clock is activated, and latch the even-number data in a section in which the positive clock is inactivated, and an odd-number data buffering unit configured to: sample odd-number data from the input data, amplify and output the odd-number data in a section in which a negative clock is activated, and latch the odd-number data in a section in which the negative clock is inactivated.

Abstract: In response to a notification of a fault captured in a system, a fault isolator serially analyzes each clock object to determine captured faults associated with the clock object. For each of the clock objects determined to have a captured fault, the fault isolator initiates a repair action for the chip represented by the clock object. The fault isolator concurrently analyzes the non-clock objects to determine captured faults associated with the non-clock objects after analysis of the clock objects. For each of the non-clock objects determined to have a captured fault, the fault isolator initiates a repair action for the chip represented by the non-clock object.

Abstract: A method for creating an architecture to support Q-gating for launch-off-shift (LOS) scan testing using a plurality of flip-flops is provided. The method may include applying a common clock signal to each clock input of the plurality of flip-flops and applying a gated scan enable signal to each scan enable input of the plurality of flip-flops. The method may further include applying a global scan enable signal directly to each of a plurality of Q-gates corresponding to each of the plurality of flip-flops, wherein the global scan enable signal traverses a signal path that bypasses combinational logic located between any two flip-flops of the plurality of flip-flops.

Abstract: A computing device has one or more processors and memory storing programs executed by the one or more processors. The computing device initializes a main application on a first thread. The main application has a first synchronous connection with a target application. After the main application performs one or more operations at the target application through the first synchronous connection, the computing device initializes an assistant process on a second thread. The assistant process has a second synchronous connection with the target application and an asynchronous connection with the main application. After receiving a request from the main application through the asynchronous connection, the assistant process performs one or more operations at the target application through the second synchronous connection.

Abstract: An integrated circuit (IC) generates clock delay control signals based on its operational voltage level. The clock delay control signals are routed to corresponding clock gating logic that controls the synchronous capturing of the outputs of corresponding signal paths. The clock gating logic delays the clock signal used by the corresponding flip-flop in response to an assertion of the corresponding received clock delay control. Thus, the clock signal used to capture the outputs of certain signal paths may be delayed under certain voltage conditions. This selective clock path delay for different signal paths enables the IC to use a higher clock frequency, or more reliably latch the path outputs at a certain clock frequency, even though different signal paths may exhibit different relative path delays under different operating voltage conditions.

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: A multi-link input/output (I/O) interface uses both feed-forward and feedback signaling to reduce the impact of noise on data capture at a memory controller. To transfer data from a source module to a destination module, a defined pattern is communicated from the memory module along a master channel concurrent with the memory module providing data via one or more slave channels. Based on the phase of the defined pattern as it is received, the multi-link I/O interface feeds forward to the slave channels control signaling whose phase reflects a predicted noise pattern for the system. Each slave channel performs CDR by adjusting timing of its corresponding capture clock signal based on the fed forward control signaling and based on feedback signaling for the corresponding slave channel, whereby the feedback signaling reflects an error measurement between a phase of a capture clock signal and transitions in received data.

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, each clock domain having one capture clock and a plurality of scan cells, each capture clock comprising a plurality of capture clock pulses; said method comprising: (a) generating and shifting-in N test stimuli to all said scan cells within said N clock domains in said integrated circuit or circuit assembly during a shift-in operation; (b) applying an ordered sequence of capture clocks to all said scan cells within said N clock domains, the ordered sequence of capture clocks comprising at least 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 said scan cells to locate any faults therein.

Abstract: An arrangement including at least one path, at least one replica path, the at least one replica path corresponding to a respective path, a controller configured to use control information derived from the at least one replica path, at least one of the paths comprising a monitoring unit configured to provide monitor information to the controller, the controller being configured to modify the control information in dependence on the monitor information.

Abstract: A computer system includes a processor, and the processor includes at least one interface for communicating with an electronic component. Each of the at least one interface has a set of interface settings. The computer system further includes a memory containing machine executable instructions. Execution of the instructions causes the processor to: monitor communications traffic on the at least one interface; store, eye distribution data acquired during the monitoring of the communications traffic in a database; compare the eye distribution data to a set of predetermined criteria; and generate a set of updated interface settings if the eye distribution does not satisfy the set of predetermined criteria.

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: Background scan cells are selected from scan cells in a circuit based on specified bit distribution information for a plurality of test cubes generated for testing the circuit. A main portion and a background portion are then determined for each test cube in the plurality of test cubes. The background portion corresponds to the background scan cells. Test cubes in the plurality of test cubes that have compatible main portions are merged into test cube groups. Each test cube group in the test cube groups comprises a main test cube and background test cubes. A main test cube, supplied by a tester or a decompressor, may be shifted into the scan chains. A background test cube may be shifted into background chains and be inserted into the main test cube in the scan chains based on control 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: A device test architecture and interface is provided to enable efficient testing embedded cores within devices. The test architecture interfaces to standard IEEE 1500 core test wrappers and provides high test data bandwidth to the wrappers from an external tester. The test architecture includes compare circuits that allow for comparison of test response data to be performed within the device. The test architecture further includes a memory for storing the results of the test response comparisons. The test architecture includes a programmable test controller to allow for various test control operations by simply inputting an instruction to the programmable test controller from the external tester. The test architecture includes a selector circuit for selecting a core for testing. Additional features and embodiments of the device test architectures are also disclosed.

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: In operation, a transmitting device selects a synchronization pattern associated with the desired timeslot that is at least mutually exclusive from synchronization patterns associated with other timeslots on the same frequency in the system. Once selected, the transmitting device transmits a burst embedding the synchronization pattern that was selected, where appropriate. If the receiving device detects the synchronization pattern, it immediately synchronizes with the timeslot with confidence that it is synchronizing to the desired timeslot by using sets of synchronization patterns associated with the desired timeslot that are at least mutually exclusive from synchronization patterns associated with the other timeslots on the same frequency.

Abstract: A scan test circuit includes: a pulse generator, for generating differential pulses according to a system clock signal; a functional path, including: a D-type latch clocked by the differential pulses; a test path, including: a scan latch clocked by a test clock signal; and a tri-state inverter. When a test enable signal is enabled, the generation of the differential pulses is disabled.

Abstract: A semiconductor device includes a compression block configured to compare and compress data of a plurality of core array blocks, by a unit of a group; a combination block configured to combine outputs of the compression block and output compression data; and a control block configured to latch the compression data and output latched data, and drive the latched data and the compression data and output resultant data to a first data line and a second data line.

Abstract: To decrease the burden of digital processing, provided is an AD conversion apparatus comprising a pattern generating section that, for each target bit specified one bit at a time moving downward in the output data, generates a pattern signal having a pulse width or number of pulses corresponding to a weighting of the target bit; an integrating section that integrates the pattern signals according to a judgment value for judging a value of the target bit each time a pattern signal is generated, and outputs a reference signal obtained by accumulating the integrated value of each pattern signal; a comparing section that, each time generation of a pattern signal is finished, compares the input signal to the reference signal; and an output section that outputs the output data to have values corresponding to the comparison results obtained after each generation of a pattern signal corresponding to a bit is finished.

Abstract: Functional circuits and cores of circuits are tested on integrated circuits using scan paths. Using parallel scan distributor and collector circuits for these scan paths improves test access of circuits and cores embedded within ICs and reduces the IC's power consumption during scan testing. A controller for the distributor and collector circuits includes a test control register, a test control state machine and a multiplexer. These test circuits can be connected in a hierarchy or in parallel. A conventional test access port or TAP can be modified to work with the disclosed test circuits.

Abstract: An integrated circuit is configured to receive a test clock input and includes circuitry configured to generate test clocks from the test clock input, and test circuitry configured to use the test clocks in a test mode.

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: Aspects of the invention relate to test generation techniques for test-per-clock. Test cubes may be generated by adding constraints to a conventional automatic test pattern generator. During a test cube merging process, a first test cube is merged with one or more test cubes that are compatible with the first test cube to generate a second test cube. The second test cube is shifted by one bit along a direction of scan chain shifting to generate a third test cube. The third test cube is then merged with one or more test cubes in the test cubes that are compatible with the third test cube to generate a fourth test cube. The shifting and merging operations may be repeated for a predetermined number of times.

Abstract: An apparatus has a large block of synchronous logic arranged to include a first partition and a second partition. The first partition is configured to receive a first clock signal during a functional mode and during a test mode. The second partition is configured to receive the first clock signal during the functional mode, and the second partition configured to receive a second clock signal during a test mode. The second clock signal has the same frequency as the first clock signal. The second clock signal has a different phase from the first clock signal.