1259results about "Digital circuit testing" patented technology

A main power supply continuously provides a current to a power input terminal of an integrated circuit device under test (DUT). The DUT's demand for current at the power input terminal temporarily increases during state changes in synchronous logic circuits implemented within the DUT. To limit variation (noise) in voltage at the power input terminal arising from these temporary increases in current demand, a charged capacitor is connected to the power input terminal during each DUT state change. The capacitor discharges into the power input terminal to supply additional current to meet the DUT's increased demand. Following each DUT state change the capacitor is disconnected from the power input terminal and charged to a level sufficient to meet a predicted increase in current demand during a next DUT state change.

A method and apparatus for tracing hardware states using dynamically reconfigurable test circuits provides improved debug and troubleshooting capability for functional logic implemented within field programmable logic arrays (FPGAs). Special test logic configurations may be loaded to enhance the debugging of a system using FPGAs. Registers are used to capture snapshots of internal signals for access by a trace program and a test multiplexer is used to provide real-time output to test pins for use with external test equipment. By retrieving the hardware snapshot information with a trace program running on a system in which the FPGA is used, software and hardware debugging are coordinated, providing a sophisticated model of overall system behavior. Special test circuits are implemented within the test logic configurations to enable detection of various events and errors. Counters are used to capture count values when system processor execution reaches a hardware trace point or when events occur. Comparators are used to detect specific data or address values and event detectors are used to detect particular logic value combinations that occur within the functional logic.

The present invention discloses a testing circuit and method for thin film transistor display array, for testing the yield of thin film transistor array. The testing circuit comprising: An array tester, a test panel (DUT), a sense amplifier array. The sense amplifier is composed by a plurality of trans- impedance amplifier unit and a plurality of parasitic capacitance discharge circuit unit. Every sense amplifier includes: a trans-impedance amplifier, which is implemented by an operational amplifier, two switches and an operation capacitance, the trans-impedance amplifier is used to form an integrated circuit, the output is transmitted to a sampling/hold circuit via a switch; a parasitic capacitance discharge circuit is used to form a discharge rout for the charge of the parasitic capacitance.

An integrated circuit system has a reference data table for holding information that is used to control at least one circuit block in the system and also has a power supply circuit, a body bias control circuit, a clock delivery circuit, a temperature monitor circuit, and/or a configuration control circuit. The performance of the system is improved by obtaining system performance data by testing the system at different supply voltages, different body-bias voltages, different clock speeds, and/or different temperatures. Values based on the data are entered into the reference data table. The power supply circuit, the body bias control circuit, the clock delivery circuit, and/or the temperature monitor circuit data is adjusted using the entered values.

A system and method of ensuring hardware security of a device, such as an integrated circuit having secure data stored thereon. The integrated circuit or other hardware device can implement one or more configurable fuses that limit access to one or more secure locations within the device. The secure locations may contain secure data. The state of the configurable fuses can be ensured, thereby limiting access to secure locations, by forcing the occurrence of a logical state prior to allowing access to hardware locations configured by the fuses. A configurable non-secure access code can be used to force the occurrence of the logical state. Receipt of the non-secure access code by the hardware device forces the occurrence of the hardware state, thereby ensuring access only to those secure locations configured by the fuses.

A method for testing a semiconductor device with a multi-gigabit communications receiver includes combining a data output from a high-speed communications transmitter with a perturbation signal generated by automatic test equipment. The combined signal data signal including jitter and low voltage swings is input to the communications receiver port under test. The automatic test equipment determines the bit error rate of the parallel data output from the receiver port under test. This test method is appropriate for semiconductor devices with multiple transceiver ports.

Techniques and systems for analysis, diagnosis and debugging fabricated hardware designs at a Hardware Description Language (HDL) level are described. Although the hardware designs (which were designed in HDL) have been fabricated in integrated circuit products with limited input/output pins, the techniques and systems enable the hardware designs within the integrated circuit products to be comprehensively analyzed, diagnosed, and debugged at the HDL level at speed. The ability to debug hardware designs at the HDL level facilitates correction or adjustment of the HDL description of the hardware designs.

A method and apparatus for locating integrated circuit defects associated with different aspects of the integrated circuit industry. The integrated circuit is configured in a known failing mode, with a first power supply providing a constant voltage and variable current. Next, one or more additional dedicated power supplies are connected to various points of interest throughout the integrated circuit, wherein these dedicated power supplies have a preset current and the voltage is allowed to vary. The integrated circuit is then scanned with a laser beam, which induces current changes on in the integrated circuit especially in defective areas. These current changes then cause voltage changes on the dedicated power supplies. When such a voltage change occurs on the dedicated power supplies, its position is noted.

Embodiments of the invention include on-chip characterization of transistor degradation. In one embodiment, includes one or more functional blocks to perform one or more functions and an integrated on-chip characterization circuit to perform on-chip characterization of transistor degradation. The integrated on-chip characterization circuit includes a selectively enabled ring oscillator to generate a reference oscillating signal, a free-running ring oscillator to generate a free-running oscillating signal, and a comparison circuit coupled to the selectively enabled ring oscillator and the free-running ring oscillator. From the reference oscillating signal and the free-running oscillating signal, the comparison circuit determine a measure of transistor degradation.

A method and a system for compensating for a permutation of L pairs of cable such that the compensation is localized in a trellis decoder of a receiver. The L pairs of cable correspond to L dimensions of a trellis code associated with the trellis decoder. The trellis code includes a plurality of code-subsets. The permutation of the L pairs of cable is determined. A plurality of sets of swap indicators based on the permutation of the L pairs of cable is generated. Each of the sets of swap indicators corresponds to one of the code-subsets. The code-subsets are remapped based on the corresponding sets of swap indicators.

A wireless integrated circuit test method and system is presented. The invention allows testing of one or more integrated circuits configured with a wireless interface and a test access mechanism which controls input of test data received over a wireless connection from a test station to test structures which test functional blocks on the integrated circuit. Via the wireless connection, multiple integrated circuits or similarly equipped devices under test can be tested simultaneously. The invention also enables concurrent testing of independently testable functional blocks on any given integrated circuit under test.

An integrated circuit tester produces an output TEST signal following a pulse of a reference CLOCK signal with a delay that is a sum of an inherent drive delay and an adjustable drive delay. The tester also samples an input RESPONSE signal following a pulse of the reference CLOCK signal with a delay that is a sum of an inherent compare delay and an adjustable compare delay. The inherent drive and compare signal path delays within an integrated circuit tester are measured by first connecting a salphasic plane to transmission lines that normally convey signals between the tester and terminals of an integrated circuit device under test. A standing wave signal appearing on that salphasic plane is phase locked to the CLOCK signal so that a zero crossing of the standing wave occurs at a fixed interval after each pulse of the CLOCK signal. Each transmission line concurrently conveys the standing wave to the tester to provide timing references for measuring the inherent drive and compare signal path delays within the tester. Transmission line signal paths are also measured. Delays are added to the drive and compare signal paths to compensate for the measured inherent drive, compare and transmission line delays.

An integrated circuit is operable to measure tolerance to jitter in a data stream signal. A Clock And Data Recovery Circuit (“CDR”) thereon recovers a phase of a clock for sampling a data stream signal containing a repeatable known sequence of data values and then samples the data stream signal with the recovered clock phase to obtain data stream sample data. An error rate determination circuit independently generates the repeatable known sequence of data values and compares them with the data stream sample data to determine an associated error rate. A control circuit coupled to the CDR delays the recovered clock phase by a predetermined amount a plurality of times and monitors the error rate after each time it delays the recovered clock phase. In this way, a maximum delayed clock phase is determined, representing a right timing signal margin for which the data stream signal can be sampled.

A data retention system has master-slave latches for holding data in an active mode; a data retention latch for preserving data read from the master latch in a sleep mode, which is connected to the master latch in parallel with the slave latch; a first multiplexer for receiving data externally provided and feedback data from the data retention latch, and selectively outputting either the data externally provided or the feedback data to the master latch in response to a first control signal; and a second multiplexer for transferring output data of the master latch to the slave latch and the data retention latch in response to a second control signal, wherein power for the data retention latch remains turned on in the sleep mode, while power for the data retention system except for the data retention latch is turned off. The data retention latch may include gate transistors controlled by the second control signal and a data holding unit having transistors for holding data transferred through the gate transistors, wherein the gate transistors and the transistors in the data holding unit have a high-threshold voltage.

Trigger reception on different instrumentation devices may be synchronized by each instrumentation device generating one or more trigger enable signals and delaying performance of an operation in response to a trigger signal until a transition in a trigger enable signal. An instrumentation system may include several instrumentation devices and a communication medium coupling the instrumentation devices. One of the instrumentation devices may process data in response to a sample clock signal. That instrumentation device may also generate a trigger enable signal and delay performing an operation in response to a trigger signal transmitted via the communication medium until a transition in the trigger enable signal occurs. The trigger enable signal is not the sample clock signal. The trigger enable signal may be synchronized to another trigger enable signal generated by another one of the instrumentation devices.

The invention discloses a field programmable gate array (FPGA)-based integrated circuit testing system, and a method for testing a digital-analog hybrid integrated circuit chip provided with a digital module or using a digital module as a main module and provided with a few analog modules by using the testing system. The system mainly comprises a personal computer (PC) machine, a main control chip, a FPGA chip, configuration information storage equipment and testing vector storage equipment. The testing method is implemented by the following steps that: the main control chip configures the FPGA chip, the main control chip sends a testing command to the FPGA chip, the FPGA chip sends an excitation signal to a chip to be tested and acquires the output response of the chip to be tested, or the analog parameter module acquires analog output response, the FPGA chip compares the output response or the analog output response of the chip to be tested with the testing information and judges the consistency of the output response and the testing information, and the chip to be tested is an accepted product or a defective product is judged. The system and the method can be widely applied in the field of integrated circuit chip test.

A method for managing a pattern object file in a modular test system is disclosed. The method includes providing a modular test system, where the modular test system comprises a system controller for controlling at least one site controller, and where the at least one site controller controls at least one test module and its corresponding device under test (DUT). The method further includes creating an object file management framework for establishing a standard interface between vendor-supplied pattern compilers and the modular test system, receiving a pattern source file, creating a pattern object metafile based on the pattern source file using the object file management framework, and testing the device under test through the test module using the pattern object metafile.

A system for testing a high speed integrated circuit includes a test device having a test clock with a first maximum frequency for performing level sensitive scan design (LSSD) testing of the integrated circuit device under test, a frequency multiplier circuit for multiplying the test clock signal to a higher second frequency capable of operating the device under test, and a finite state machine for generating a first internal clock for testing the device under test. In a practical embodiment, the internal clock speed may be running at a frequency many multiples of the test clock. Alternatively, a method of testing a device under test (DUT) at design speed includes running a predetermined group of tests with a test device operating at a lower speed than the design speed; incorporating LSSD or boundary scan test techniques in the device under test, together with a frequency multiplying device; generating a global clock for the device under test from the frequency multiplying circuit and using a finite state machine as a synchronizer and pulse generator to control a capture clock with respect to the global clock.

Scan chains to support debugging and manufacturing test modes for integrated circuit chips are made adaptable. Scan chains may be configured either in a multiple scan chain JTAG mode or in a multiple independent and parallel scan chain mode. The configuration transition between the scan modes is made by private instructions implemented in a JTAG controller, which supports the IEEE 1149.1 standard.

The invention relates to a detecting device and a detecting method for the single event effect of a SPARC processor; the detecting device comprises a testing circuit board, a high-speed data collect and control unit, a main control computer and a dual-way power-supply system; through dual-thread control, the testing circuit board and the main control computer can realize simultaneous monitoring for single event latch and other single event effects; the testing circuit can be flexibly provided with a tested processor and a monitoring processor to carry out self-test and dual-processor supporting test; the hardware structure of the device can suit to all kinds of the single event effects of the SPARC processor; the device can realize the different testing for all kinds of the single event effects, and can solve the problem of measuring the single event effects of the SPARC processor in the environment of ground simulative radiation.

Circuits and methods for measuring and characterizing random variations in device characteristics of semiconductor integrated circuit devices, which enable circuit designers to accurately measure and characterize random variations in device characteristics (such as transistor threshold voltage) between neighboring devices resulting from random sources such as dopant fluctuations and line edge roughness, for purposes of integrated circuit design and analysis. In one aspect, a method for characterizing random variations in device mismatch (e.g., threshold voltage mismatch) between a pair of device (e.g., transistors) is performed by obtaining subthreshold DC voltage characteristic data for the device pair, and then determining a distribution in voltage threshold mismatch for the device pair directly from the corresponding subthreshold DC voltage characteristic data. The voltage threshold mismatch distributions of different device pairs of a given circuit design can then be used to determine voltage threshold variations of the constituent circuit devices. The voltage threshold variation of the devices can be used to characterize the random variations of the given circuit.

According to one embodiment, a programmable logic assembly (200) may include a nonvolatile memory (202) may be coupled to an associated volatile programmable logic device (PLD) (204). Built-in-self-test (BIST) data (208) may be stored in a nonvolatile memory (202) that places the volatile PLD (204) in a self-test configuration. If a volatile PLD (204) passes a self-test, user data (210) may be stored in a nonvolatile memory (202) that places a volatile PLD (204) into a user determined configuration.

In a lock-step synchronism fault-tolerant computer system including a plurality of computing modules having a processor and a memory in which each computing module processes the same instruction string in synchronization with each other. When detecting disagreement in a state of access to an external bus among the respective processors in each computing module, if no fault is detected in the system including each computing module, processing of resuming operation in synchronization is executed with respect to each computing module after generating an interruption to all the processors to execute delay adjustment for making a state of instruction execution among computing modules be coincident.

There is a desire to provide a testing method and apparatus that can be successfully integrated into a PLL and PLL-like circuits (e.g. frequency synthesizers, delay lock loops, etc.). It is desirable that the PLL or PLL-like circuit integrated with testing apparatus does not suffer from performance degradations during nominal (mission mode) operation. Furthermore, it is desirable that the PLL and the testing apparatus share the same interface. In order to produce a PLL having integrated testing apparatus, without having the PLL suffer severe performance degradations during nominal operation nor having the combination of the PLL and testing apparatus be unnecessarily large, a modified PLL integrated with testing apparatus is provided.

The invention provides a method and circuit for measuring on-chip, cycle-to-cycle, jitter. Copies of a circuit comprising a programmable delay line, a programmable phase comparator, and two counters are placed at different locations on an IC near a clock signal. The programmable delay line creates a clock signal that is delayed by one clock cycle. This delayed clock signal is compared in time to the original clock signal by the programmable phase comparator. If the difference in time between the delayed clock signal and the clock signal is greater than the dead time, the first counter is triggered. If the difference in time is negative and the absolute value is greater than the dead time, the second counter is triggered. A statistical distribution, based on the values of the counters, is created. This distribution is used to predict on-chip, cycle-to-cycle jitter.

A parallel processing pattern generation system for an integrated circuit tester includes two pattern memories, a main pattern generator, and two auxiliary pattern generators. Each pattern memory may receive and store data patterns from a host computer before the test. All three pattern generators may produce data pattern sequences in a variety of ways by executing separately stored algorithmic programs. The pattern sequences generated by each of the two auxiliary pattern generators separately address the two pattern memories so that either one or both of the two pattern memories may read out pattern data during a test. The main pattern generator includes a routing circuit for receiving as inputs a portion of the pattern data generated by the main pattern generator itself and the pattern data read out of the two pattern memories. The routing circuit, controlled by another portion of the pattern data produced by the main pattern generator, selects from among its inputs on a bit-by-bit, cycle-by-cycle basis to provide pattern data for controlling tester activities during each cycle of a test.

A method and system for monitoring and compensating the performance of an operational circuit is provided. The system includes one or more integrated circuit chips and a controller. Each integrated circuit chip includes one or more operational circuits, each operational circuit having at least one controllable circuit parameter. Each integrated circuit chip also includes a process monitor module at least partially constructed thereon. The controller is coupled to each process monitor module and to each operational circuit. The controller includes logic for evaluating the performance of an operational circuit based on data obtained from process monitor module and operational circuit related data stored in a memory. Based on the evaluation, the controller determines whether any deviations from desired or optimal performance of the circuit exist. If deviations exist, the controller generates a control signal to initiate adjustments to the operational circuit to compensate for the deviations.

A method for managing multiple hardware test module versions, software components, and tester operating system (TOS) versions in a modular test system is disclosed. The method includes installing the TOS versions compatible with the modular test system in an archive and installing vendor software components corresponding to the hardware test module versions in the archive. The method further includes creating system profiles for describing vendor software components corresponding to the hardware test module versions and the TOS versions, selecting a system profile for the modular test system, where the system profile includes a set of compatible vendor software components and a selected TOS for testing a particular hardware test module version, and activating the selected TOS on the modular test system.

A jitter generator produces a jittery test signal for use in performing a jitter test on an integrated circuit (IC) device under test (DUT). The jitter generator includes a programmable delay circuit for delaying a non-jittery input signal with a varying delay controlled by input digital delay control data to produce the test signal. A pattern generator supplies a sequence of delay control data to the programmable delay circuit causing it to produce a desired jitter pattern in the test signal. During a calibration process, a measurement unit feeds the test signal back to the input of the programmable delay circuit, causing the test signal to oscillate with a period proportional to the delay through the delay circuit. The measurement unit then measures the period of the test signal for various values of delay control data and reports measurement results. Based on the measurement results, host equipment then determines an appropriate sequence of delay control data for producing a desired jitter pattern in the test signal and programs the pattern generator to produce that sequence of delay control data during a jitter test. The jitter generator can form a part of a built-in, self-test (BIST) circuit implemented within the DUT itself.

The invention discloses an automatic test system for a digital integrated circuit. The automatic test system is composed of a tested chip, a test interface board, an integration module, a test module, a control module, a display module and an upper computer. The control module is connected with the upper computer. The test module is connected with the control module. A base pin of the tested chip is connected with the test interface board which is connected with the test module. The integration module is connected with the test module and the upper computer. The display module is connected with the control module and displays a waveform after final comparison by the aid of upper computer software, so that the automatic test for functions and performance of the chip is completed. The automatic test system is low in cost, easy to implement under laboratory conditions, easy and convenient to operate, high in development rate and capable of meeting the test requirements of small-batch products. According to the system, through an automatic test, the problem that operation is complex due to the fact that the number of test items is large in a manual test is solved, the test efficiency is enhanced, a misjudgment caused by artificial factors in the manual test is avoided, and therefore test quality is improved.