Systems and methods for a sequential decompressor which builds equations predictably provide a first-in, first out (“FIFO”) shift register which is fed by a first XOR decompressor and provides outputs to a second XOR decompressor.

Systems and methods efficiently bring additional variables into a Pseudo-Random Pattern Generator (“PRPG”) in the early cycles of an automatic test pattern generation (“ATPG”) process without utilizing any additional hardware or control pins. Overscanning (e.g., scanning longer than the length of the longest channel) for some additional cycles brings in enough variables into the PRPG. Data corresponding to earlier cycles of the ATPG process is removed.

The disclosure describes novel methods and apparatuses for accessing test compression architectures (TCA) in a device using either a parallel or serial access technique. The serial access technique may be controlled by a device tester or by a JTAG controller. Further the disclosure provides an approach to access the TCA of a device when the device exists in a daisy-chain arrangement with other devices, such as in a customer's system. Additional embodiments are also provided and described in the disclosure.

Embodiments herein relate to apparatus, systems, and methods to compress a test pattern onto a field programmable gate array to test a device under test. This may include identifying values of a plurality of drive pins for a plurality of test cycles to apply to an input of the DUT for each of the plurality of test cycles, identifying values of a plurality of compare pins for the plurality of test cycles to compare an output of the DUT, respectively, for each of the plurality of test cycles, analyzing the identified values, compressing, based on the analysis, the values of the plurality of drive pins and the plurality of compare pins, and storing the compressed values on the FPGA.

A method includes injecting scan patterns into an input of a decompressor that distributes the scan patterns to a plurality of scan chains whose outputs are coupled to inputs of a compressor, which provides a compressed scan test result representing the plurality of scan chains. The method also includes, in response to the compressed scan test result being indicative of failure, identifying a particular scan chain of the plurality of scan chains that is responsible for the failure by a debug circuit that is coupled to the input of the decompressor and to a compressor output. The debug circuit enables an output of any single scan chain of the plurality of scan chains to be available at the compressor output while suppressing outputs of all other scan chains of the plurality of scan chains.

This application provides decompression circuits. An example decompression circuit includes a plurality of sub-circuits. The sub-circuit includes a plurality of cellular automaton (CA) circuits and a phase shifter. Each of the plurality of CA circuits includes a first XOR circuit and a register. The first XOR circuit includes a first input end, a second input end, and an output end. A data input end of the register is coupled to the output end of the first XOR circuit. A data output end of the register is coupled to the first input end of the first XOR circuit and an input end of the phase shifter. The data output end of the register is further coupled to the second input end of the first XOR circuit in a different CA circuit. The phase shifter is configured to output a test signal.

A circuit comprises: scan chains comprising scan cells, the scan chains configured to shift in test patterns, apply the test patterns to the circuit, capture test responses of the circuit, and shift out the test responses; a decompressor configured to decompress compressed test patterns into the test patterns; a test response compactor configured to compact the test responses; and shuffler circuitry inserted between outputs of the scan chains and inputs of the test response compactor, the shuffler circuitry comprising state elements configured to delay output signals from some of the scan chains for one or more clock cycles based on a control signal, the control signal varying with the test patterns.

A system-on-chip (SoC) is disclosed. The SoC includes a set of input channels, a first partition including a set of output wrapper chains, a set of output channels, a second partition including a set of input wrapper chains, and an inter-partition circuit coupled between the first and second partitions. During an external test mode, the set of input channels receives input test data. The set of output wrapper chains receives and stores intermediate data that is generated based on the input test data. The inter-partition circuit receives the intermediate data from the set of output wrapper chains and generates test response data based on the intermediate data. The set of input wrapper chains receives the test response data, and provides the test response data to be captured as output test data at the set of output channels to test the inter-partition circuit.

Disclosed herein are method, system, and storage-medium embodiments for single-pass diagnosis of multiple chain defects in circuit-design testing. Embodiments include processor(s) to select a plurality of a scan chains in a circuit under test and determine presence of at least a first defect in the first scan chain, and a second defect in the first scan chain or in the second scan chain. The plurality of scan chains may include specific scan chains that each have respective pluralities of scan cells. Processor(s) may map the first defect to a first range of first scan cells, and the second defect to a second range of second scan cells. Based at least in part on a failing capture-pattern set, processor(s) may locate the first defect in a first scan cell of the first range, and the second defect in a second scan cell of the first range or the second range.

The present disclosure generally relates to an embedded physical layer (EPHY) for a field programmable gate array (FPGA). The EPHY for the FPGA is for a testing device that can receive and transmit in both the high speed PHYs, as well as low speed PHYs, such as MIPI PHYs (MPHYs), to meet universal flash storage (UFS) specifications. The testing device with the EPHY for the FPGA provides flexibility to support any specification updates without the need of application specific (ASIC) production cycles.