Abstract: A die-to-die repeater circuit includes a transmit circuit coupled to a die-to-die interconnect, the transmit circuit including at least one flip flop to function as a part of a linear feedback shift register (LFSR) to transmit a value across the die-to-die interconnect for design for test (DFT) to check proper operation of the die-to-die interconnect, and a receive circuit coupled to the die-to-die interconnect, the receive circuit including at least one flip flop to function as part of a multiple input shift register (MISR).

Abstract: In one embodiments, a system comprises: a plurality of scan test chains configured to perform test operations at a first clock speed; a central test controller for controlling testing by the scan test chains; and an interface configured to generate instructions to direct central test controller. The interface communicates with the centralized test controller at the first clock speed and an external scan input at a second clock speed. The second clock speed can be faster than the first clock speed. The instructions communicated to the central controller can be directions associated with sequential scan compression/decompression operations. In one exemplary implementation, the interface further comprise a mode state machine used to generate the mode control instructions and a test register state machine that generate test state control instructions, wherein the test mode control instructions and the test state control instructions direct operations of the centralized test controller.

Abstract: In one embodiment, a system comprises: a global clock input for receiving a global clock, a plurality of partitions; and a skew tolerant interface configured to compensate for clock skew differences between a global clock from outside at least one of the partitions and a balanced local clock within at least one of the partitions. The partitions can be test partitions. The skew tolerant interface can cross a mesochronous boundary. In one exemplary implementation, the skew tolerant interface includes a deskew ring buffer on communication path of the at least one partition. pointers associated with the ring buffer can be free-running and depend only on clocks being pulsed when out of reset. The scheme can be fully synchronous and deterministic. The scheme can be modeled for the ATPG tools using simple pipeline flops. The depth of the pipeline can be dependent on the pointer difference for the read/write interface. The global clock input can be part of a scan link.

Abstract: In one embodiment, a test system comprises: a plurality of test partitions and a centralized controller configured to coordinate testing between the plurality of test partitions. At least one of the plurality of test partitions comprises: a partition test interface controller configured to control testing within at least one test partition in accordance with dynamic selection of a test mode, and at least one test chain configured to perform test operations. The dynamic selection of the test mode and control of testing within a test partition can be independent of selection of a test mode and control in others of the plurality of test partitions. In one embodiment, a free running clock signal is coupled to a test partition, and the partition test mode controller transforms the free running clock signal into a local partition test clock which is controlled in accordance with the dynamic selection of the test mode.

Abstract: A method for testing. An external clock frequency is generated. Test data is supplied over a plurality of SSI connections clocked at the external clock frequency, wherein the test data is designed for testing a logic block. A DSTA module is configured for the logic block that is integrated within a chip to a bandwidth ratio, wherein the bandwidth ratio defines the plurality of SSI connections and a plurality of PSI connections of the chip. The external clock frequency is divided down using the bandwidth ratio to generate an internal clock frequency, wherein the bandwidth ratio defines the external clock frequency and the internal clock frequency. The test data is scanned over the plurality of PSI connections clocked at the internal clock frequency according to the bandwidth ratio, wherein the plurality of PSI connections is configured for inputting the test data to the plurality of scan chains.

Abstract: Granular dynamic test systems and methods facilitate efficient and effective timing of test operations. In one embodiment, a chip test system comprises: a first test partition operable to perform test operations based upon a first local test clock signal; a second test partition operable to perform test operations based upon a second local test clock signal; and a centralized controller configured to coordinate testing between the plurality of test partitions, wherein the coordination includes managing communication of test information between the plurality of test partitions and external pins. In one exemplary implementation, a trigger edge of the first local test clock signal is staggered with respect to a trigger edge of the second local test clock signal, wherein the stagger is coordinated to mitigate power consumption by test operations in the first test partition and test operations in the second test partition.

Abstract: A method for testing. The method includes sending a single instruction over a JTAG interface to a JTAG controller to select a first internal test data register of a plurality of data registers. The method includes programming the first internal test data register using the JTAG interface to configure mode control access and state control access for a test controller implementing a sequential scan architecture to test a chip at a system level.

Abstract: In one embodiment, a test system comprises: a test partition configured to perform test operations; a centralized test controller for controlling testing by the test partition; and a test link interface controller configured to communicate between the centralized test controller and the test partition, wherein the test link interface controller controls dynamic changes to external pads associated with the test operations. The test link interface controller dynamically selects between an input direction and output direction for the external pads. The test link interface includes a pin direction controller that generates direction control signals based on the state of local test controller and communicates the desired direction to a boundary scan cell associated with the pin. The boundary scan cell programs the pad to either input or output direction depending on direction control signals. The input direction corresponds to driving test data and the output direction corresponds to observing test data.

Abstract: A die-to-die repeater circuit includes a transmit circuit coupled to a die-to-die interconnect, the transmit circuit including at least one flip flop to function as a part of a linear feedback shift register (LFSR) to transmit a value across the die-to-die interconnect for design for test (DFT) to check proper operation of the die-to-die interconnect, and a receive circuit coupled to the die-to-die interconnect, the receive circuit including at least one flip flop to function as part of a multiple input shift register (MISR).

Abstract: One embodiment of the present invention sets forth an integrated circuit that includes multiple input/output (I/O) pad groups. Each I/O pad group includes an on-chip star network, multiple I/O pads, multiple test multiplexers, a digital-to-analog converter (DAC), and a wide-range comparator. Each test multiplexer is configured to couple a different I/O pad to the on-chip star network. The DAC is configured to supply at least one of a source current, a sink current, and a first reference voltage to the on-chip star network. The wide-range comparator is configured to compare a voltage present on a first I/O pad included in the plurality of I/O pads with a second reference voltage. Advantageously, IO leakage and DC parametric testing may be performed on integrated circuits with high I/O pad counts using an ATE system with a significantly lower quantity of ATE test channels relative to prior approaches.

Abstract: Efficient scan system presented can comprise: an array including a plurality of array non scannable components and a plurality of array quasi-scannable components wherein each column of the array includes at least one of the plurality of array quasi-scannable components; and an input interface configured to receive and selectively forward data and scan information to at least a portion of the array. At least a portion of the plurality of array quasi-scannable components can form a diagonal pattern in the array. The input interface can include: an input interface selection component wherein an output of the input interface selection component is communicatively coupled to an input of the input interface quasi-scannable component associated with one row and an input of the input interface selection component is communicatively coupled to an output of one of the plurality of array quasi-scannable components associated with another row.

Abstract: In one embodiment, a multiple input signature register (MISR) shadow works with a MISR to compress test responses of a layout partition in a functional region of an integrated circuit. In operation, for each test pattern in a test pattern split, the MISR generates a MISR signature based on the responses of the layout partition. As the test patterns in the test pattern split execute, the MISR shadow accumulates the MISR signatures and stores the result as MISR shadow data. After the final test pattern included in the test pattern split executes, the MISR shadow combines the bits in the MISR shadow data to form a single bit MISR shadow status that indicates whether the layout partition, and therefore the functional region, responds properly to the test pattern split. By efficiently summarizing the test responses, the MISR shadow optimizes the resources required to identify defective functional regions.

Abstract: In one embodiment, a multiple input signature register (MISR) shadow works with a MISR to compress test responses of a layout partition in a functional region of an integrated circuit. In operation, for each test pattern in a test pattern split, the MISR generates a MISR signature based on the responses of the layout partition. As the test patterns in the test pattern split execute, the MISR shadow accumulates the MISR signatures and stores the result as MISR shadow data. After the final test pattern included in the test pattern split executes, the MISR shadow combines the bits in the MISR shadow data to form a single bit MISR shadow status that indicates whether the layout partition, and therefore the functional region, responds properly to the test pattern split. By efficiently summarizing the test responses, the MISR shadow optimizes the resources required to identify defective functional regions.

Abstract: In one embodiment, a system comprises: a global clock input for receiving a global clock, a plurality of partitions; and a skew tolerant interface configured to compensate for clock skew differences between a global clock from outside at least one of the partitions and a balanced local clock within at least one of the partitions. The partitions can be test partitions. The skew tolerant interface can cross a mesochronous boundary. In one exemplary implementation, the skew tolerant interface includes a deskew ring buffer on communication path of the at least one partition. pointers associated with the ring buffer can be free-running and depend only on clocks being pulsed when out of reset. The scheme can be fully synchronous and deterministic. The scheme can be modeled for the ATPG tools using simple pipeline flops. The depth of the pipeline can be dependent on the pointer difference for the read/write interface. The global clock input can be part of a scan link.

Abstract: A method for testing. The method includes sending a single instruction over a JTAG interface to a JTAG controller to select a first internal test data register of a plurality of data registers. The method includes programming the first internal test data register using the JTAG interface to configure mode control access and state control access for a test controller implementing a sequential scan architecture to test a chip at a system level.

Abstract: Granular dynamic test systems and methods facilitate efficient and effective timing of test operations. In one embodiment, a chip test system comprises: a first test partition operable to perform test operations based upon a first local test clock signal; a second test partition operable to perform test operations based upon a second local test clock signal; and a centralized controller configured to coordinate testing between the plurality of test partitions, wherein the coordination includes managing communication of test information between the plurality of test partitions and external pins. In one exemplary implementation, a trigger edge of the first local test clock signal is staggered with respect to a trigger edge of the second local test clock signal, wherein the stagger is coordinated to mitigate power consumption by test operations in the first test partition and test operations in the second test partition.

Abstract: In one embodiment, a test system comprises: a test partition configured to perform test operations; a centralized test controller for controlling testing by the test partition; and a test link interface controller configured to communicate between the centralized test controller and the test partition, wherein the test link interface controller controls dynamic changes to external pads associated with the test operations. The test link interface controller dynamically selects between an input direction and output direction for the external pads. The test link interface includes a pin direction controller that generates direction control signals based on the state of local test controller and communicates the desired direction to a boundary scan cell associated with the pin. The boundary scan cell programs the pad to either input or output direction depending on direction control signals. The input direction corresponds to driving test data and the output direction corresponds to observing test data.

Abstract: In one embodiments, a system comprises: a plurality of scan test chains configured to perform test operations at a first clock speed; a central test controller for controlling testing by the scan test chains; and an interface configured to generate instructions to direct central test controller. The interface communicates with the centralized test controller at the first clock speed and an external scan input at a second clock speed. The second clock speed can be faster than the first clock speed. The instructions communicated to the central controller can be directions associated with sequential scan compression/decompression operations. In one exemplary implementation, the interface further comprise a mode state machine used to generate the mode control instructions and a test register state machine that generate test state control instructions, wherein the test mode control instructions and the test state control instructions direct operations of the centralized test controller.

Abstract: In one embodiment, a test system comprises: a plurality of test partitions and a centralized controller configured to coordinate testing between the plurality of test partitions. At least one of the plurality of test partitions comprises: a partition test interface controller configured to control testing within at least one test partition in accordance with dynamic selection of a test mode, and at least one test chain configured to perform test operations. The dynamic selection of the test mode and control of testing within a test partition can be independent of selection of a test mode and control in others of the plurality of test partitions. In one embodiment, a free running clock signal is coupled to a test partition, and the partition test mode controller transforms the free running clock signal into a local partition test clock which is controlled in accordance with the dynamic selection of the test mode.

Abstract: A method for testing. An external clock frequency is generated. Test data is supplied over a plurality of SSI connections clocked at the external clock frequency, wherein the test data is designed for testing a logic block. A DSTA module is configured for the logic block that is integrated within a chip to a bandwidth ratio, wherein the bandwidth ratio defines the plurality of SSI connections and a plurality of PSI connections of the chip. The external clock frequency is divided down using the bandwidth ratio to generate an internal clock frequency, wherein the bandwidth ratio defines the external clock frequency and the internal clock frequency. The test data is scanned over the plurality of PSI connections clocked at the internal clock frequency according to the bandwidth ratio, wherein the plurality of PSI connections is configured for inputting the test data to the plurality of scan chains.