Abstract: A design-for-test (DFT) circuitry is disclosed. The DFT circuitry includes a first multiplexer operable to transfer one of a clock signal or an inverted clock signal based on a clock polarity control signal. The DFT circuitry also includes a burst counter coupled to the first multiplexer. The burst counter is operable to output a signal at a first logic state for a predefined pulse count. The DFT circuitry also includes a second multiplexer that is operable to output one of the clock polarity control signal or the clock signal according to a signal output from the burst counter. The DFT circuitry may also include a third multiplexer that forwards control signals identifying the predefined pulse count to the burst counter from different sources such as an external pin, a programmable interconnect, and a memory element.

Abstract: A device tester is provided. The device tester includes a probe card and a substrate coupled to the probe card. The substrate has a plurality of layers for routing a signal. An integrated circuit is coupled to the substrate. The integrated circuit is operable to transmit an input signal received from a testing apparatus to a device under test through the substrate to a signal probe. The signal probe is further operable to receive a test signal from the device under test in response to the input signal, wherein the integrated circuit is operable to amplify the test signal, and transmit the amplified test signal to the testing apparatus.

Abstract: A design-for-test (DFT) circuitry is disclosed. The DFT circuitry includes a first multiplexer operable to transfer one of a clock signal or an inverted clock signal based on a clock polarity control signal. The DFT circuitry also includes a burst counter coupled to the first multiplexer. The burst counter is operable to output a signal at a first logic state for a predefined pulse count. The DFT circuitry also includes a second multiplexer that is operable to output one of the clock polarity control signal or the clock signal according to a signal output from the burst counter. The DFT circuitry may also include a third multiplexer that forwards control signals identifying the predefined pulse count to the burst counter from different sources such as an external pin, a programmable interconnect, and a memory element.

Abstract: A programmable integrated circuit may contain multiple logic blocks. Computing equipment may be used to run automated tools that process a design for the programmable integrated circuit to perform corresponding circuit tests. A translation tool may translate a transistor-level description of circuitry on the programmable integrated circuit into a gate-level description. A block-level test configuration data generation tool may generate block-level test configuration data files. The test configuration data files may be used as constraints for an automatic test pattern generation tool that produces block-level test vectors. A full-chip propagation tool may use the block-level test vectors, block-level test configuration data files, and full-chip constraints to produce corresponding full-chip test configuration data and full-chip test vectors for testing the integrated circuit. A translation tool may convert the configuration data and test vectors into a tester file.

Abstract: Integrated circuits (ICs) with configurable test pins and a method of testing an IC are disclosed. An IC has input/output (I/O) pins that can be configured either as a test input pin, a test output pin or a user I/O pin. Selector circuits are used to selectively route and couple the I/O pins to various logic blocks and test circuitry on the IC. Selector circuits are also used to selectively couple either a user output or a test output to different I/O pins on the IC. Switches are used to configure the selector circuits and route test signals within the IC. Different configurations of the switches determine how the signals are routed. Test input signals from an I/O pin may be routed to any test circuitry within the IC and test output signals from a test circuit may be routed to any I/O pin on the IC.

Abstract: An integrated circuit is provided with built-in-self test circuitry. The integrated circuit may have multiple blocks of memory. The memory may be tested using the built-in-self test circuitry. Each memory block may include a satellite address generator that is used in generating test addresses for the memory blocks. Each memory block may also include failure analysis logic and output response analyzer logic. Stalling logic may be used to individually stall memory block testing on a block-by-block basis during memory tests. Address buffer circuitry such as first-in-first-out buffers may be used to provide randomized memory addresses during testing.

Abstract: An integrated circuit is provided with built-in-self test circuitry. The integrated circuit may have multiple blocks of memory. The memory may be tested using the built-in-self test circuitry. Each memory block may include a satellite address generator that is used in generating test addresses for the memory blocks. Each memory block may also include failure analysis logic and output response analyzer logic. Stalling logic may be used to individually stall memory block testing on a block-by-block basis during memory tests. Address buffer circuitry such as first-in-first-out buffers may be used to provide randomized memory addresses during testing.

Abstract: An integrated circuit may have a circuit under test. The integrated circuit may have a clock generation circuit that receives a reference clock from a tester and that generates a corresponding core clock. The integrated circuit may have a built in self test circuit and a clock synthesizer that receives the core clock. The built in self test circuit may provide clock synthesizer control signals that direct the clock synthesizer to produce test clock signals at various test clock frequencies. The test clock at the test clock frequencies may be applied to the circuit under test during circuit testing. The circuit under test may assert a pass signal when the circuit tests are completed successfully. The built in self test circuit may inform the tester of the maximum clock frequency at which the circuit under test successfully passes testing.

Abstract: Built-in self test techniques for testing circuit blocks on integrated circuits are provided. A BIST controller is provided on-chip to test two or more circuit blocks. High routing congestion is avoided by loading test data into the circuit blocks through scan chain segments that run continuously along the inputs and outputs of the circuit blocks. The BIST controller takes control of the scan chain segments during test and has the ability to partition the scan chains at specified intervals.

Abstract: A programmable integrated circuit has multiple power supply voltages. Power supply voltages are distributed using power supply distribution lines. The integrated circuit has programmable power supply voltage selection switches. Each power supply voltage selection switch has its inputs connected to the power supply distribution lines and supplies a selected power supply voltage to a circuit block at its output. Test circuits are provided for testing the power supply voltage selection switches. During testing, the power supply voltage selection switches are adjusted to produce various power supply voltages at their outputs. The test circuit associated with each switch performs voltage comparisons to determine whether the switch is functioning properly. Each test circuit produces a test result based on its voltage comparison. The test results from the test circuits are provided to a scan chain, which unloads the test results from the integrated circuit to a tester for analysis.

Abstract: A scan testing technique in which test data is pipelined to scan logic within an integrated circuit. In system on a programmable chip (SOPC) designs, pipelines are easily built in the programmable logic device (PLD) logic by configuring programmable interconnects to connect registers in a pipelined manner so that test data can be pipelined to scan the logic under test. In system on a chip (SOC) designs, a smart test generator-analyzer is configured to recursively extract pipeline information from a design-so that test data can be pipelined to scan the logic under test. Generally, test data is pipelined using existing functional logic and/or scan chains. Furthermore, a failure analysis (FA) platform is described. The FA platform is operable to take as its input a failing vector as well as a pipelined scan vector and unroll the pipeline sequence to determine which vector caused the failure.

Abstract: Integrated circuits such as programmable logic device integrated circuits are provided that have memory arrays. The memory arrays can be tested using configurable built in self test circuitry. The built in self test circuitry may have test control register circuitry and configurable state machine logic. The state machine logic may perform at-speed tests on a memory array and may provide test results to external equipment for analysis. A tester may be used to provide test control settings to the test control register circuitry. The test control settings may include march element settings for a march sequence. During testing, the configurable state machine logic may use the march element settings to generate march sequences. March sequences that have been generated in this way may be used in testing the memory array.

Abstract: A technique and device for testing integrated circuits is implemented by comparing similar test outputs for differences. One particular type of integrated circuit that may benefit from this method of testing is a programmable logic integrated circuit. Separate logic units in the integrated circuit receive test patterns and generate outputs based on the test patterns. A comparator is then used to compare the outputs. If one output differs from the other outputs, an error message is created and test result information is stored in memory for use in pinpointing the cause of the error signal. In other embodiments, a microprocessor or embedded processor core may be configured to provide test patterns or used for comparison of the test pattern outputs.

Abstract: Techniques are provided that control the generation of test routes to improve the ability of a test system to isolate defects on programmable circuits. A test generator creates test routes that test the horizontal resources. In these test routes, the inputs of each circuit element are only connected to other circuit elements in the same row. Test routes are also generated to test the vertical resources. Each of theses test routes is allowed to make only one transition from between two different rows of circuit elements. The configuration generator includes a post processor that ensures all source drivers in the test routes connect to at least two sinks.

Abstract: A programmable logic device test generation tool is provided that produces test configuration data and test vectors for testing programmable logic device integrated circuits. A graph generation tool converts a netlist or other circuit description of a programmable logic device integrated circuit into a graph having nodes and edges. A timing analysis tool may be used to help produce test constraints. Based on the test constraints, an automatic test generator processes the graph to produce the test configuration data and test vectors. In processing the graph with the automatic test generator, the graph may be divided into multiple testable subgraphs. Each subgraph may be processed using an iterative approach in which a cost function threshold is adjusted in a number of steps until a target test coverage is obtained or processing saturates.

Abstract: A memory device provides improved tolerance against soft errors. A guardian memory cell is connected with a single memory cell or multiple memory cells, which may be unrelated or associated with a single programmable device component. When a guardian cell stores a first guardian value, the connected memory cells are held to a first bit value. When a guardian cell stores a second value, each of the connected memory cells can store either the first bit value or a second bit value. The guardian cell is adapted to activate a pull-down or pull-up transistor of each connected memory cell to hold the connected memory cells to the first bit value. The first bit value is selected to maximize the number of memory cells protected by guardian cells.

Abstract: An interlinked chain of exclusive-or (XOR) logic gates and registers is formed by connecting a first input of each XOR logic gate to an output of a preceding register, and by connecting an input of each register to an output of a preceding XOR logic gate. Each XOR logic gate has a second input connected to receive an output from a respective data source. The interlinked chain further includes an originating XOR logic gate having its first input connected to an output of an originating data source rather than to a preceding register. The interlinked chain includes a terminating XOR logic gate having an output defined to provide an encrypted signature for the various data source outputs. Destructible bypass connections are provided to enable direct access to each data source in a secure environment and permanently disable direct access to each data source prior to release from the secure environment.

Abstract: Programmable logic devices may use shadow memory for gathering diagnostic information while testing memory blocks. Memory block testing may be performed at any clock speed allowed during normal operation in a system such as the highest allowed clock speed. Built in self test circuitry and address and data paths are formed by loading configuration data into a programmable logic device. During write operations on a memory block under test, test data words are written into the memory block. A comparator compares data words read from the memory block to expected data words received from the test pattern generator to produce corresponding comparison data words. The comparison data words are written into the shadow memory. The same addresses are applied to the memory block under test and the shadow memory, so the stored comparison data words form a test results bit map indicative of errors in the memory block.

Abstract: A method for analyzing a structured integrated circuit is provided. The method includes identifying a random logic region of the structured integrated circuit. The structured integrated circuit includes a predefined layout for transistors and basic interconnections to define a set of logic elements. A tile array of basic logic cells is integrated throughout the identified random logic region. The tile array of basic logic cells is defined from the set of logic elements of the structured integrated circuit. The tile array of basic cells enables communication of testing signals along the tile array of basic logic cells in a first and a second direction. The first and second directions are different from one another. The testing signals help to identify one or more errors in the tile array of basic logic cells. The array format assists in diagnosing and curing defects in the tile array of basic logic cells. The errors are pinpointed to a basic logic cell at the intersection of the first and second direction.

Abstract: Techniques are provided for testing routing resources that route control signals on programmable integrated circuits (ICs). Control signals (such as clock signals) are routed through a logic gate to a test register. Values of the control signals are stored in the test register, transmitted outside the IC, and then compared to expected values to identify defects in the programmable interconnections. An enable circuit couples the control signals to functional registers on the programmable IC during user mode. The enable circuit decouples the control signals from the functional registers so that the control signals do not interfere with tests of the functional registers during test mode. During the test procedures, the control signals are treated as data signals and are not used to control other registers on the IC.