Abstract: A scan clock modifier, a method of providing a variable scan clock, an IC including a scan clock modifier and a library including a cell of a scan clock modifier. In one embodiment, the scan clock modifier includes: (1) logic circuitry configured to provide at least one selected clock signal based on a test scan clock signal and a first clock control signal, both of the test scan clock signal and the first clock control signal received from test equipment and (2) comparison logic configured to provide a scan clock signal based on the at least one selected clock signal and at least one other clock control signal received from the test equipment, wherein the first and the at least one other clock control signals are different clock control signals.

Abstract: A computer-readable medium stores therein a program that causes a computer to execute acquiring for each chip, first delay values of paths in chips manufactured using circuit information concerning a circuit-under-test; building a function model representing a delay value of a path, based on the first delay values for the path and the circuit information; calculating a second delay value of a path included in and having the same configuration in each chip, using a built function model and the circuit information; comparing for each chip, a given calculated second delay value and the first delay value of a given path having a configuration identical to that of the path for which the given second delay value has been calculated; determining based on a comparison result, the given path to be a path that includes a delay error occurring irregularly according to chip; and outputting a determination result.

Abstract: A clock and data recovery device recovers data from a sequential stream of data that includes bursts of data separated by gaps. Each burst of data arrives with its own phase and with its own deviation from a nominal frequency. The bursts of data begin with a preamble that is utilized to determine the timing of the burst. The clock and data recovery device determines the timing of a burst of data using signals from one or more demultiplexers or samplers. At the start of each burst of data, sampled input signals are analyzed by an edge detector to determine a sample phase for the burst. A selector utilizes the sample phase determined by the edge detector to choose which of the sampled input signals to use to produce output data signals from the clock and data recovery device.

Abstract: Clock control circuitry for an integrated circuit, a method of testing an integrated circuit having a clock gate, an integrated circuit and a library of cells including the clock control circuitry are provided. In one embodiment, the integrated circuit includes: (1) a clock gate configured to apply a clock signal to at least a first scan chain of the integrated circuit, (2) combinational logic coupled to an input of the clock gate and (3) Design-for-Test logic located external to the combinational logic and coupled to the clock gate and a first cell of a second scan chain of the integrated circuit, the Design-for-Test logic configured to control operation of the clock gate based on a logic value of the first cell.

Abstract: A method for adjusting timing of multiple cores within an integrated circuit includes selecting a reference core and a target core from among a plurality of cores of an integrated circuit. Self-test circuitry of the integrated circuit is used to generate a response signature for each of the reference core and the target core. The response signature of the reference core is compared with the response signature of the target core. A local clock buffer of the target core is adjusted until the response signature of the target core matches the response signature of the reference core.

Abstract: A device and a method detect an acceleration of a logic signal expressed by a closeness, beyond a closeness threshold, of at least two variation edges of the logic signal. A first control bit and a second control bit are provided. At each edge of the logic signal, the value of the first control bit is inverted after a first delay and the value of the second control bit is inverted after a second delay. An acceleration is detected when the two control bits have at the same time their respective initial values or their respective inverted initial values. Application is in particular but not exclusively to the detection of error injections in a secured integrated circuit.

Abstract: In a first embodiment a TAP 318 of IEEE standard 1149.1 is allowed to commandeer control from a WSP 202 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.

Abstract: An integrated circuit device includes a plurality of functional tiles. Each functional tile may be configured into a scan chain. A clock generator is operable to generate an internal clock signal that is distributed to each of the functional tiles. A clock gater is associated with each of the functional tiles. Each clock gater is operable to receive an external enable signal and the internal clock signal, generate a scan clock signal for loading a test pattern into the scan chain based on the external enable signal and the internal clock signal, and generate at least one capture clock signal for capturing a response of the tile to the test pattern responsive to identifying the loading of the test pattern.

Abstract: A pattern matching accelerator (PMA) for assisting software threads to find the presence and location of strings in an input data stream that match a given pattern. The patterns are defined using regular expressions that are compiled into a data structure comprised of rules subsequently processed by the PMA. The patterns to be searched in the input stream are defined by the user as a set of regular expressions. The patterns to be searched are grouped in pattern context sets. The sets of regular expressions which define the pattern context sets are compiled to generate a rules structure used by the PMA hardware. The rules are compiled before search run time and stored in main memory, in rule cache memory within the PMA or a combination thereof. For each input character, the PMA executes the search and returns the search results.

Abstract: An extraction unit of fault assumption and a finish-point FF is provided, the fault assumption is selected from fault assumption information, and a logic trace is executed from the fault assumption toward an output side. A test result of a finish-point FF obtained as a result of the trace from the fault assumption is determined. The maximum value and the minimum value of the propagation route up to the finish-point FF are determined, and a delay margin is determined from the values. A delay range is determined by using the delay margin and the test result, and a fault candidate and a delay range of the delay fault are specified by the process of the determination of the fault candidate and the delay range.

Abstract: A shift register circuit for providing plural scan signals and plural emission signals includes a plurality of shift register stages. Each shift register stage includes a scan signal generation module and an emission signal generation module. The scan signal generation module is utilized for generating a first scan signal and a second scan signal according to a first clock and a second clock having a phase opposite to the first clock. The first and second scan signals have pulses opposite to each other. The pulse width of the first scan signal is substantially twice that of the first clock. The emission signal generation module is utilized for generating an emission signal according to a third clock and a fourth clock having a phase opposite to the third clock. The pulse width of the emission signal is substantially identical to that of the third clock.

Abstract: Disclosed is a system and method for improving the linearity of a clock and data recovery (CDR) circuit. In one embodiment, a data stream is received, and the phase of a clock signal is adjusted using two interpolators. The phase of the output signal of the second interpolator is adjusted simultaneously with, and complementary to, adjusting the phase of the first interpolator. The first interpolator's output signal is injected into a first delay cell in a delay loop having a plurality of delay cells, and the output of the second interpolator is inactivated. When the maximum phase of the first interpolator's output signal is reached, the second interpolator's output signal is injected into another one of the delay cells, and the first interpolator's output signal is inactivated. The data stream is then recovered using the output of the delay loop as a clock signal.

Abstract: In an embodiment of the invention, variable test clock circuitry is provided within an integrated circuit desired to be tested. The variable test clock frequency implements a test clock control register that receives serial test data from a device tester and is configured to serially pass the received test data to scan test chains within the integrated circuit. The test clock control register stores test clock information. The test clock information is provided to a test clock generator where the test clock generator then produces test clock signals at a predetermined frequency. The test clock signal is then provided as a test clock frequency for the scan test chains within the integrated circuit. Methods are also disclosed for operating the variable test clock frequency.

Abstract: A system for testing multi-clock domains in an integrated circuit (IC) includes a plurality of clock sources coupled to a plurality of clock controllers. Each of the clock sources generates a fast clock associated with one of the multi-clock domains. Each of the clock controllers is configured to provide capture pulses to test one clock domain. The capture pulses provided to a clock domain are at a frequency of a fast clock associated with the clock domain. The clock controllers operate sequentially to provide the capture pulses to test the clock domains.

Abstract: The invention disclosed herein provides increased effectiveness of delay and transition fault testing. The method of delay fault testing integrated circuits comprises the steps of creating a plurality of test clock gating groups. The plurality of test clock gating groups comprising elements defining inter-element signal paths within the integrated circuit. Each of the elements of the plurality of test clock gating groups share clock frequency and additional shared characteristics. At least one test signal is commonly and selectively connected through at least one low-speed gate transistor to each of the elements comprising each of the plurality of test clock gating groups based on membership in the test clock gating group. This invention can also be practiced using scan-enable gating groups for the same purposes.

Abstract: Systems, controllers, and methods are disclosed, such as an initialization system including a controller configured to receive patterns of read data coupled from a memory device through a plurality of read data lanes. The controller is operable to detect lane-to-lane skew in the patterns of read data. The controller then adjusts the manner in which the read data received through the read data lanes during normal operation are divided into frames. The controller can also couple patterns of command/address bits to the memory device through a plurality of command/address lanes. The memory device can send the received command/address bits back to the controller through the read data lanes. The controller is operable to detect any lane-to-lane skew in the patterns of command/address bits received through the read data lanes to adjust the manner in which the command/address bits coupled through the command/address lanes during normal operation are divided into frames.

Abstract: In an embodiment of the invention, an integrated circuit with several clock domains bank is tested by first disabling a PLL clock and scanning test data into scan chains. Next delay fault testing (DFT) code is transmitted to each distributed clock divider on the integrated circuit. The PLL clock is then enabled to the distributed clock dividers. Selected clock dividers generate launch pulses that allow test data to be propagated from the scan chains into circuit blocks in the clock domains. Capture pulses are then generated by selected distributed clock dividers to capture test data coming form the circuit blocks into the scan chains. Next the PLL clock is disabled and the test data is scanned from the scan chains to an on-chip test control circuit.

Abstract: A digital functional test system incorporating both digital stimulus and digital response/compare capability for digital electronic circuitry. The system includes a chassis and a single width VME eXtensions for Instrumentation (VXI) module arranged in or on the chassis. The single width VXI module includes a timing sub-module that generates a stimulus clock signal and a response clock signal, eight pattern sub-modules, and a master oscillator sub-module that provides a clock signal. Each pattern sub-module receives the stimulus and response clock signals, and the clock signal from the master oscillator sub-module, and includes a pattern generating module, a stimulus memory component that stores stimulus data outgoing from the pattern generating module, a response memory component that records response data incoming to the pattern generating module, and a compare reference memory component that provides a reference for a compare function of the recorded response data in the response memory component.

Abstract: Methods and corresponding test systems for generating a chip facility waveform from a series of chip snapshots. The methods including, (i) testing an integrated chip multiple times, each time increasing a clockstop delay delaying a clockstop generated by triggered error condition each time determining the state of state holding elements of the integrated circuit and (ii) testing an integrated circuit chip one time to generate a error condition and determining multiple times the states of state holding elements of the integrated circuit based on previous states of the state holding elements.

Abstract: A memory controller receives data and phase-providing signals from a memory device. The phase-providing signal is not a clock signal, but is used by the memory controller to phase align a local data-sampling signal with the incoming data. The memory controller samples the data signal with the data-sampling signal. The memory controller can perform maintenance operations to update the phase relationship between the phase-providing and data-sampling signals.

Abstract: A method and apparatus for conducting transition testing using scan elements are disclosed. In one embodiment, an integrated circuit (IC) includes a scan chain having first and second subsets of scannable flops, the first subset having respective data inputs coupled to a memory array. The scannable flops of the second subset may each have a respective data input coupled to circuitry other than the memory array (e.g., to a logic circuit). The scannable flops of the first subset may be enabled for scan shifting during a transition test mode. The scannable flops of the second subset are inhibited from scanning during the transition test mode. The transition test mode may include at least two functional clock cycles in which the scannable flops of the first subset provide complementary first and second logic values to logic circuits coupled to respective data outputs.

Abstract: An error addition apparatus receives a data signal D having a frame format having a specific signal inserted into its front, adds errors to the data signal D, and outputs a resulting signal. The apparatus has an error addition regulation unit for receiving a frame synchronization signal F, indicative of a timing at which the front of the frame of the data signal has been inputted, and regulating the errors such that the errors are added to positions other than a region of the specific signal. Accordingly, errors are not added to a specific signal.

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: Clock signal control circuitry is disclosed along with a method for switching a clock between modes and a computer program product. The clock signal control circuitry is for receiving a clock signal from a clock signal generator and for outputting said clock signal to synchronous circuitry that is to be clocked by said clock signal.

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 plurality of scan chains coupled to the additional circuitry, a scan capture clock generator configured to generate a scan capture clock signal having a controllable number of capture pulses, and a clock selection circuit configured to select between at least the scan capture clock signal and a scan shift clock signal for application to clock signal inputs of the scan chains. In one embodiment, the scan capture clock generator comprises a finite state machine, a plurality of capture clock pulse circuits each generating a capture clock pulse signal comprising a different number of capture clock pulses, and logic circuitry coupled to the finite state machine and having inputs adapted to receive the outputs of the capture clock pulse circuits.

Abstract: A test board includes a plurality of test modules. Each test module stores a first control signal, a data signal, and a second control signal in response to a clock signal, and tests a corresponding device under test (DUT) using the first control signal and the stored data signal in response to the second control signal to generate an error signal indicating whether the DUT is defective. Each test module outputs the first control signal, the data signal, and the second control signal to a test module in a next stage, and each test module of a subsequent stage receives the error signal stored generated by a test module in a previous stage in response to the clock signal.

Abstract: In a system in which a plurality of modules have different operational rates and a common clock controlling data delivery to the modules, the rate at which data is delivered to the system can be maximized using a return clock signal to prevent the loss of synchronization of the modules. A clocking error signal may be produced when the clock signal makes a transition to a logic state that may cause loss of synchronization between the modules.

Abstract: A method is provided to evaluate whether one or more test patterns is power safe for use during manufacturing testing of an integrated circuit that includes a nonuniform power grid and that includes a scan chain, the method comprising: assigning respective toggle count thresholds for respective power grid regions of the non-uniform power grid; and determining whether respective numbers of toggles by scan elements of the scan chain within one or more respective power grid regions meet respective toggle count thresholds for the one or more respective regions during at least one scan-shift cycle in the course of scan-in of a test pattern to the scan chain.

Abstract: A low-pin-count scan compression method and apparatus for reducing test data volume and test application time in a scan-based integrated circuit. The scan-based integrated circuit contains one or more scan chains, each scan chain comprising one or more scan cells coupled in series. The method and apparatus includes a programmable pipelined decompressor comprising one or more shift registers, a combinational logic network, and an optional scan connector. The programmable pipelined decompressor decompresses a compressed scan pattern on its compressed scan inputs and drives the generated decompressed scan pattern at the output of the programmable pipelined decompressor to the scan data inputs of the scan-based integrated circuit. Any input constraints imposed by said_combinational logic network are incorporated into an automatic test pattern generation (ATPG) program for generating the compressed scan pattern for one or more selected faults in one-step.

Abstract: A tester for testing high-speed serial transceiver circuitry. The tester includes a jitter generator that uses a rapidly varying phase-selecting signal to select between two or more differently phased clock signals to generate a phase-modulated signal. The phase-selecting signal is designed to contain low- and high-frequency components. The phase-modulated signal is input into a phase filter to filter unwanted high-frequency components. The filtered output of the phase filter is input into a data-transmit serializer to serialize a low-speed parallel word into a high-speed jittered test pattern for input into the transceiver circuitry.

Abstract: A method is provided for testing an integrated circuit comprising multiple cores, with at least two cores having different associated first and second clock signals of different frequencies. A test signal is provided using a clocked scan chain clocked at a test frequency (TCK). A transition is provided in a clock circuit reset signal (clockdiv_rst) which triggers the operation of a clock divider circuit (44) which derives the first and second clock signals (clk_xx, clk_yy, clk_zz) from an internal clock (40) of the integrated circuit. The first and second clock signals thus start at substantially the same time, and these are used during a test mode to perform a test of the integrated circuit. After test, the test result is output using the clocked scan chain clocked at the test frequency (TCK).

Abstract: A blanking primitive masking circuit has a detection and handling circuit that receives data containing blanking primitives. The detection and handling circuit generates a dynamic blanking signal when blanking primitives are detected. The received data is delayed and provided to a pattern detector that generates a synchronization signal provided to a memory and a phase sync signal provided to the detection and handling circuit and to a comparator. The comparator receives reference data from the memory, the delayed data, and the dynamic blanking signal. The comparator compares the reference data with the delayed data and generates bit error outputs from mismatched reference data bits and delayed data bits when the dynamic blanking signal from the detection and handling circuit is absent and suppressing the generation bit error outputs when the blanking primitive are in the delay data and the dynamic blanking signal is present.

Abstract: An integrated circuit includes a bypass signal path exchanging, between transceivers which are included in the integrated circuit, a signal transmitted/received between a transceiver of the transceivers and an internal logic circuit which processes data being input/output by transceiver with bypassing the internal logic circuit, a switch switching a pathway of the bypass signal path, and a switch changeover controller transferring a switch control signal that performs a changeover of the switch.

Abstract: A scan architecture and design methodology yielding significant reduction in scan area and power overhead is generally presented. In this regard, an apparatus is introduced comprising a plurality of combinatorial logic clouds, scan cells coupled with the combinatorial logic clouds, the scan cells to load test vectors, wherein the scan cells comprise a plurality of first type scan cells and second type scan cells sequentially coupled with separate combinatorial logic cloud outputs, and a first scan clock and a second scan clock, wherein the first scan clock controls the first type scan cells and the second scan clock controls the second type scan cells. Other embodiments are also described and claimed.

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: A method is provided to evaluate whether one or more test patterns is power safe for use during manufacturing testing of an integrated circuit that includes a nonuniform power grid and that includes a scan chain, the method comprising: assigning respective toggle count thresholds for respective power grid regions of the non-uniform power grid; and determining whether respective numbers of toggles by scan elements of the scan chain within one or more respective power grid regions meet respective toggle count thresholds for the one or more respective regions during at least one scan-shift cycle in the course of scan-in of a test pattern to the scan chain.

Abstract: A method of testing an electronic device is disclosed. The electronic device includes an embedded controller. The method includes storing a type information of the embedded controller and transmitting the type information to an application module through a data module. The application module analyzes the type information to obtain a command. The application module sends the command to the embedded controller. The embedded controller returns a testing result to the application module. The application module generates a testing report after the application module compares the testing result with a predetermined result.

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: 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: A non-fighting fully clocked scan latch is described that is dynamically configurable to support both logic data latching and scan data latching. The described scan latch circuit design reduces a load placed on a logic data latch portion of the described circuit by a scan latch portion of the described circuit, and thereby increases the speed of the described scan latch to that of an output latch without scan capability. Power required to drive the described scan latch is reduced by clocking the circuit to avoid fighting and by reducing the number of transistors included in transistor stacks internal to the scan latch. By reducing drive power requirements, eliminating internal latch fighting, and increasing latch response, a versatile scan latch is achieved that may be successfully implemented in a wide range of circuits despite the use of different supply drive voltage, threshold voltage, source-to-drain voltage, and transistor technology combinations.

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 soft-function trigger state machine includes state machine logic defined to use a scan-in waveform to sample a scan-clock waveform to obtain a sampled data pattern. The state machine logic is defined to compare the sampled data pattern to a soft action pattern to determine whether the sampled data pattern matches the soft action pattern. The state machine logic is also defined to trigger an action associated with the soft action pattern when the sampled data pattern matches the soft action pattern.

Abstract: An optimized JTAG interface is used to access JTAG Tap Domains within an integrated circuit. The interface requires fewer pins than the conventional JTAG interface and is thus more applicable than conventional JTAG interfaces on an integrated circuit where the availability of pins is limited. The interface may be used for a variety of serial communication operations such as, but not limited to, serial communication related integrated circuit test, emulation, debug, and/or trace operations.

Abstract: An integrated circuit (IC) is disclosed that comprises a circuit portion (100) having a plurality of inputs (102) and a plurality of outputs (106), the plurality of inputs being arranged to receive a test pattern in a test mode of the integrated circuit, the test pattern comprising a plurality of test vectors for feeding to the plurality of inputs in successive clock cycles. The IC also comprises a test arrangement for testing the circuit portion (100), comprising a test pattern generator (110) for generating the test pattern, masking logic (150) for masking selected outputs of the plurality of outputs (106) and a signal generator (130) coupled to the masking logic (150) for generating a masking signal triggering the masking of all of said circuit portion outputs during selected cycles of the successive clock cycles, the signal generator (130) being responsive to clock cycle selection data (s1-st).

Abstract: Delay-fault testing and parametric analysis systems and methods utilizing one or more variable delay time-base generators. In embodiments of the delay-fault testing systems, short-delay logic paths are provided with additional scan-chain memory elements and logic that, in conjunction with the one or more variable-delay time-base generators, provides the effect of over-clocking without the need to over-clock. Related methods provide such effective over-clocking. In embodiments of parametric analysis systems, test point sampling elements and analysis circuitry are clocked as a function of the output of the one or more variable-delay time-base generators to provide various parametric analysis functionality. Related methods address this functionality.

Abstract: A system and method for detecting hold path faults in an integrated circuit is provided in exemplary embodiments. These exemplary embodiments introduce a method of identifying data paths within an integrated circuit with statistically the highest timing slack among the data paths within the integrated circuit that cover the entire process space of the circuit. By identifying these paths (i.e., shortest data paths), a robust test pattern can be generated that directly tests for hold path faults on short data paths within the integrated circuit using one functional clock pulse.

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 semiconductor memory device includes a plurality of banks, each including a plurality of first memory cells and a plurality of second memory cells; a first input/output unit configured to transfer first data between the first memory cells and a plurality of first data pads; a second input/output unit configured to transfer second data between the second memory cells and a plurality of second data pads; a path selection unit configured to transfer the first data, which are input through the first data pads, to both the first and second memory cells during a test mode; and a test mode control unit configured to compare the first data of the first and second memory cells, and to control at least one of the first data pads to denote a fail status based on a comparison result, during the test mode.

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.