Abstract: Embodiments of the present invention generally provide methods and apparatus for testing memory devices having normal memory elements and redundant memory elements. During a front-end testing procedure, normal memory elements that are found to be defective are replaced by redundant memory elements. During the front-end test, redundant memory elements that are found to be defective may be marked as defective by blowing associated mask fuses. During a back-end testing procedure, the results of testing a normal memory element may be masked (e.g., forced to a passing result) if the normal memory element has been replaced by a redundant memory element. Similarly, the results of testing a redundant memory element may be masked if the redundant memory element was previously found to be defective, as indicated by an associated mark fuse.

Abstract: A semiconductor memory device having a mount test circuit and a mount test method thereof are provided. The test circuit for use in a semiconductor memory device including a plurality of memory blocks may include a comparison unit for comparing test data of at least two memory blocks selected from the plurality of memory blocks, deciding whether or not the test data of the selected memory blocks are identical, and outputting a pass signal or fail signal as a flag signal; and an output selection unit for selecting any one of the selected memory blocks as an output memory block, and changing the output memory block whenever the fail signal is generated from the comparison unit, thus forming it as a data output path, which may lessen error occurrence.

Abstract: A memory (10) has a memory array (12), a charge pump (18), a voltage regulator (20), a refresh control circuit (16), and a refresh counter (22). The charge pump (18) provides a substrate bias to the memory array (12). The voltage regulator (20) provides a pump enable signal for maintaining a voltage level of the substrate bias within upper and lower limits. The refresh control circuit (16) controls refresh operations. The refresh counter (22) is coupled to receive the pump enable signal, and in response, provides a refresh timing signal to the refresh control circuit (16) to control a refresh rate of the memory array (12). A programmable fuse circuit (26) is provided to program the refresh rate using the counter (22). The programmable fuse circuit (26) may be programmed during wafer probe testing or board level burn-in. A built-in self test (BIST) circuit (24) may be included to facilitate testing.

Abstract: An integrated circuit includes a first bus and at least one array of embedded memories. Each array includes a second bus such as a bidirectional bus coupled to the embedded memories and to the first bus such that test vectors in the form of data words can be written from the first bus to selected embedded memories in the array. Also included is a built-in-self-test (BIST) circuit operable to compare data words on the first bus to data words read back from the selected embedded memories through the bidirectional bus.

Abstract: A semiconductor integrated circuit has a memory collar including a memory cell configured to store a written data pattern and read and output the data pattern, and a register configured to store a failed data pattern, and a built-in self test circuit configured to write the data pattern in the memory cell, output expected value data, and decide whether to continue a test or suspend the test to output failure information to outside, based on a comparison result of the data pattern outputted from the memory cell and the expected value data and a comparison result of the data pattern and the failed data pattern.

Abstract: A method for testing functional boundary logic at an asynchronous clock boundary of an integrated circuit device is provided. With the method, each clock domain has its own scan paths that do not cross domain boundaries. By eliminating the scanning across the boundaries, the requirement to have two clock grids in the asynchronously clocked domains may be eliminated. As a result, circuit area and design time with regard to the clock distribution design are reduced. In addition, removing the second clock grid, i.e. the high speed core or system clock, in the asynchronously clocked domains removes the requirement to have a multiplexing scheme for selection of clocking signals in the asynchronous domain. In addition to the above, the system and method provide boundary built-in-self-test logic for testing the functional crossing logic of boundaries between the clock domains in a functional mode of operation.

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 test method sets a write value to a scan flip-flop for setting a value to a memory to be tested. It then performs a series of shift operation in scan paths until setting of a read value is completed. During the shift operation, a value for refresh operation is added to the value passing through the flip-flop for setting a value to the memory to be tested.

Abstract: Disclosed is a semiconductor integrated circuit that allows a fail path to be detected. A semiconductor integrated circuit as described herein can be configured to include a data register that can receive input data to generate and store a write expectation value and a read expectation value, during a period in which a test mode is activated, a first comparing unit that compares write data written in a memory cell with the write expectation value, and a second comparing unit that compares read data read from the memory cell with the read expectation value.

Abstract: In one embodiment, an apparatus comprises an interconnect; at least one processor coupled to the interconnect; and at least one memory controller coupled to the interconnect. The memory controller is programmable by the processor into a loopback test mode of operation and, in the loopback test mode, the memory controller is configured to receive a first write operation from the processor over the interconnect. The memory controller is configured to route write data from the first write operation through a plurality of drivers and receivers connected to a plurality of data pins that are capable of connection to one or more memory modules. The memory controller is further configured to return the write data as read data on the interconnect for a first read operation received from the processor on the interconnect.

Abstract: Provided are a method and system checking output from multiple execution units. Execution units concurrently execute test instructions to generate test output, wherein test instructions are transferred to the execution units from a cache coupled to the execution units over a bus. The test output from the execution units is compared to determine whether the output from the execution units indicates the execution units are properly concurrently executing test instructions. The result of the comparing of the test output are forwarded to a design test unit.

Abstract: A test method and apparatus for a semiconductor memory device is characterized by the sequentially programmed use of two test different modes. A first test mode tests at least signal line integrity for the semiconductor memory device by testing a merged set of bits line. The second test mode further tests at least signal line integrity after first separating the merged bits lines. Logical combination of test data derived from the first and second test modes are used to generate error detection signals. At least one bit line associated with a parity bit is preferable merged and separated in the foregoing approach.

Abstract: A defect analysis method for semiconductor memory includes: reading out an address bit map corresponding to an input kind of the memory macro from a database which stores address bit maps respectively corresponding to memory macro kinds; inputting size information of the memory macro; translating a logical address of a defective cell of the memory macro detected on the basis of results of an electric test measured by using a tester to a physical address of a memory macro in a standard disposition by using the input size information and the address bit map read out, of the memory macro, and generating a fail bit map in the standard disposition; inputting disposition information of the memory macro; and translating a physical address of the fail bit map in the standard disposition to a physical address of the memory macro by using the input disposition information of the memory macro, and generating a fail bit map of the memory macro.

Abstract: A method for testing semiconductor chips is disclosed. In one embodiment, a chip to be tested which has a test logic, at least one test mode is set, the test modes are executed in the chip and test results or the status of the test modes are output from the chip. The method includes providing a chip having at least one first register set having a plurality of registers and at least one second register set having a plurality of registers, at least one register of the first register set and at least one register of the second register set being 1:1 logically combined with one another. A first serial bit string is stored, the bit sequence of which can be assigned to at least one test mode, in the first register set. A bit sequence is transmitted for application of the logical combination between the first register set and the second register set to the first bit string stored in the first register set. The test results are read out by means of a serial second bit string.

Abstract: It is aimed to efficiently test devices that can transfer data at a very high bit rate. A test apparatus for testing a device under test includes a capture memory that stores thereon an output pattern received from the device under test, a header detecting section that reads the output pattern from the capture memory and detects a portion matching a predetermined header pattern in the output pattern, and a judging section that judges whether the output pattern is acceptable based on a result of comparison between a pattern, in the output pattern, which starts with the portion matching the predetermined header pattern and a corresponding expected value pattern.

Abstract: A method, and a corresponding device, provides for testing computer memory having a number of memory elements. The method includes the steps of initializing each memory element to zero, using a seeded random number generator, determining a random address that corresponds to a start point in the memory range, using the seeded random number generator, writing a random data value to the random address, repeating the two previous steps until all memory elements have been written to with random data values, conducting a refresh test of the memory range, and using the same seeded random number generator and the same written random data values, reading each of the memory elements in the memory range.

Abstract: In a test mode, a comparator compares for each column a value of data read from each memory cell connected to an activated word line with an expected value to be read from each memory cell. An error register holds error data based on a comparison result by a comparator. Each bit of the error data indicates the comparison result by the comparator for a corresponding column. Each bit is set to “0” when the comparison result for the corresponding column always indicates equality whichever word line is activated, and is set to “1” when once the comparison result for the corresponding column indicates difference.

Abstract: A memory device test system includes a signal generator providing memory command, address and write data signal to write data in a memory device and then read the data from the memory device. Each item of read data is compared to the corresponding item of write data, and fail data is produced indicative of the results of the comparison. The fail data is applied to a real time repair analyzer, which also receives an address of the read data being read to generate each item of fail data. The addresses are captured responsive to respective fail data signals to provide a record of the block, column and bit of each word of data read from a defective memory cell. The addresses are accumulated while the data are read from the memory device during testing so that a repair solution is available virtually as soon as the test has been completed.

Abstract: A method for testing semiconductor chips having a test logic unit includes: providing a chip having n different register sets, each of which has m different registers that are subdivided into m register groups each having n registers, each register group respectively having only one individual register from a register set, the m register groups being uniquely identifiable using m headers; programming the m different register groups by filling them with m first bit strings, each bit string being respectively assignable to a state of n test modes; transmitting at least one header to select a register group and the state of the n test modes and executing the state of n test modes stored in the selected register group; and using a serial second bit string to read out test results or the status of the test modes.

Abstract: An integrated circuit test controller and method defining a number N of failure events, applying the test to an integrated circuit under test by applying a predetermined sequence of input and output operations according to a test algorithm. Output data is compared to expected data, and a failure signal is generated when the output data does not correspond to the expected data. If a failure signal is generated, failure data related to the failure event is stored in a failure data register set. If the number N of failure events has been reached or if there are no more tests left, the content of the data failure register set is read out through a parallel failure data output port.

Abstract: A memory structure is provided. The memory structure includes a memory array, an error correct code (ECC) unit, and a comparator. The memory array includes at least one memory cell being written and storing at least one original data. The ECC unit is for reading at least one tested data from the at least one memory cell, correcting the at least one tested data when there is an error occurred in the at least one tested data and outputting at least one ECC data accordingly. The comparator is for determining whether the at least one original data is substantially the same as the at least one ECC data or not and outputting an output signal indicating whether the at least one memory cell passes or fails.

Abstract: Methods and apparatus for performing error correction code (ECC) coding techniques for high-speed implementations. The ECC code word is structured to facilitate a very fast single-error-detect (SED) that allows state machines to be stopped within a single cycle when an error is detected and enables a corresponding single-error-correct (SEC) operation to be performed over multiple cycles while the state machines are in a suspended mode.

Abstract: Read and write data steering logic in the I/O of a memory array is tested by providing a data bus lane for each addressable subunit of a memory array storage location. Each bus lane is connected to the data input of a comparator. A BIST controller writes test patterns to the memory through the write steering logic and reads the test patterns in parallel to test the write steering logic. The BIST controller writes test patterns to the memory in parallel and reads the test patterns through the read steering logic to test the read steering logic. In both cases, a separate comparator dedicated to each bus lane verifies that the subunit data was properly shifted between the data bus lane and memory storage location subunit. The comparators are effectively disabled during normal operations to prevent logic gate switching.

Abstract: There is provided a test apparatus for testing a memory-under-test for storing data strings to which an error correcting code has been added, having a logical comparator for comparing each data contained in the data string read out of the memory-under-test with an expected value generated in advance, a data error counting section for counting a number of data inconsistent with the expected value, a plurality of registers, provided corresponding to each of a plurality of classes, for storing an upper limit value of a number of errors contained in the data -under-test to be classified into the class, comparing sections for comparing each of the plurality of upper limit values stored in the plurality of registers with the counted value of the data error counting section and a classifying section for classifying the memory-under-test into the class corresponding to the register storing the upper limit value which is greater than the counted value.

Abstract: A method of testing a memory module comprising converting a hub of the memory module into a transparent mode, providing first data corresponding to a first address to the hub of the memory module, providing the first data of the hub of the memory module to a first address of a memory, providing first expected data to the hub of the memory module, outputting second data stored at the first address of the memory to the hub of the memory module, and comparing the second data with the first expected data.

Abstract: A memory redundancy analyzing apparatus having a tester, a queue, and a redundancy analyzer is provided. The tester includes testing portions for different types of fails, and each of the testing portions performs multiple tests on the memory locations and outputs fail information for at least a part of the memory device. The queue stores the fail information. The redundancy analyzer processes the fails using the fail information and produces a plurality of repair solutions. The types of fails include must fails and sparse fails. The fail information is transmitted to the queue, and the fail information includes at least a part of the fail information for the entire memory device. The tester can operate asynchronously from the redundancy analyzer.

Abstract: A semiconductor integrated circuit has a scan path that includes, between the output of the first logic section and the input of the functional block, a parallel path and a serial shift path for serially transferring data, and that includes first selectors for connecting the output of the first logic section or the serial shift path to the input of the functional block, and flip-flops for storing the data. The semiconductor integrated circuit further includes second selectors connected into the serial shift path of the scan path, for connecting the output of the functional block or the serial shift path to the input of the second logic section. Test data is provided from the serial shift path of the scan path to the functional block via the second selectors, and data output from the functional block is output via the second selectors after switching the second selectors.

Abstract: Each memory chip of a memory module tests a total of N data bits from X memory blocks for efficient testing and outputs N/X data bits from one of the memory blocks. A memory module includes a plurality of memory chips and a plurality of comparison units. Each comparison unit is disposed within a respective memory chip for testing a plurality of data bits from a plurality of memory blocks. In addition, each comparison unit outputs data bits from one of the memory blocks within the respective memory chip.

Abstract: A method for checking the refresh function of a memory having a refresh device includes the steps of, first, ascertaining whether or not refresh request pulses are being produced on the information memory and, if so, at what intervals of time from one another these refresh request pulses are produced. Next, a control unit for the information memory is supplied with refresh test pulses produced outside of the information memory instead of being supplied with the refresh request pulses. Then, the refresh test pulses are used to check a refresh device situated on the information memory.

Abstract: A modulated voltage signal modulated at a predetermined frequency f0 is supplied to an integrated circuit under test to be tested set at an arbitrary stationary point, and an observation signal containing information on power supply current flowing through the integrated circuit under test at the stationary point. Then, a determination signal from which DC component is removed is extracted from the observation signal and supplied to a determination device. The determination device compares the size of spectral component of the determination signal at the predetermined frequency f0 between each measurement point and determines that an error exists in the integrated circuit under test if a difference is a predetermined value or greater.

Abstract: A semiconductor memory device to which information of different data bits can be written, and a method of electrically testing the semiconductor memory device are provided. In a mode for testing a memory cell array of the semiconductor memory device, the semiconductor memory comprises a control signal generation pad capable of writing non-identical data to data input/output pads of each group when data is written to the memory cell array.

Abstract: A read control system and method for a memory device are provided. One embodiment of a system, among others, includes dump logic coupled to a data source, said dump logic configured to receive a first group of a defined slice of data and a second group of the defined slice of data; and a true dump bus and a complement dump bus configured in a wired-OR arrangement, said dump logic configured to drive the first group of data onto the true dump bus and the second group of data onto the complement dump bus.

Abstract: A test apparatus for testing a memory under test is provided, including a pattern generator generating a read address from which data is read from the memory under test and an expected value of the data read from the read address, a logical comparator comparing the read data read from the read address of the memory under test to the expected value and outputting fail data indicating pass/fail of every bit of the read data, a first fail memory storing a grouping of the read address and the fail data in a case where the read data and the expected value are not the same, a second fail memory storing fail data concerning addresses corresponding to each address of the memory under test, and an updating section updating fail data stored in the second fail memory and corresponding to the read address based on the grouping of the address and the fail data read from the first fail memory.

Abstract: The present invention provides a test apparatus that tests a plurality of memories under test. The test apparatus includes a data input-output section that gives and receives data to and from data input-output terminals of the plurality of memories under test, a test data supplying section that parallel supplies test data to the plurality of memories under test, a writing control section that parallel supplies a write enable signal to the plurality of memories under test, a reading control section that sequentially supplies a read enable signal to each of the plurality of memories under test, a comparing section that compares the test data sequentially read from the respective memories under test with an expected value, and a detecting section that detects, on condition that one test data is not identical with the expected value, a writing fail for the memory under test that outputs this test data.

Abstract: Programmable memory built-in self-test (MBIST) methods, apparatus, and systems are disclosed. Exemplary embodiments of the disclosed technology can be used, for example, to test one or more memories located on an integrated circuit during manufacturing testing.

Abstract: A method for testing a memory device is disclosed. The method includes: respectively writing at least one test data into a plurality of storage blocks in the memory device such that a plurality of first time written test data are stored in the storage blocks; in a read with write back test mode, reading the first time written test data from the storage blocks in the memory device and writing the plurality of first time written test data into the storage blocks to generate a plurality of second time written test data; and in a compress test mode, reading the plurality of second time written test data from the storage blocks by a compress test operation and determining whether the memory device operates erroneously according to the plurality of second time written test data and the test data.

Abstract: There are provided a semiconductor memory device and a method for testing the same, in which when a plurality of semiconductor memory devices are under test, tester equipment can detect which one of the semiconductor memory devices fails without a separate fail memory. The semiconductor memory device with a memory cell array includes a comparing circuit configured to compare data read after having been written for parallel bit testing with each other and outputting comparison result data; and a storage and output unit configured to latch, as pass/fail data, the comparison result data output from the comparing circuit, simultaneously output the latched comparison result data via a plurality of outputs when an enable signal is activated, and simultaneously output independently applied parallel bit test comparison data via the plurality of outputs when the enable signal is not activated.

Abstract: A method and apparatus to correctly compute a vector-gather, vector-operate (e.g., vector add), and vector-scatter sequence, particularly when elements of the vector may be redundantly presented, as with indirectly addressed vector operations. For an add operation, one vector register is loaded with the “add-in” values, and another vector register is loaded with address values of “add to” elements to be gathered from memory into a third vector register. If the vector of address values has a plurality of elements that point to the same memory address, the algorithm should add all the “add in” values from elements corresponding to the elements having the duplicated addresses. An indirectly addressed load performs the “gather” operation to load the “add to” values. A vector add operation then adds corresponding elements from the “add in” vector to the “add to” vector. An indirectly addressed store then performs the “scatter” operation to store the results.

Abstract: There is provided a memory device in which memory cells may be tested using several different test data patterns. The memory device may include a switch unit, a plurality of storage units, and a selector. The switch unit may transfer bits of data received in response to a mode control signal to memory cells or transfers bits of test data to the memory cells. The plurality of storage units respectively stores bits of test data in response to bits of an input control signal. The selector applies test data stored in one of the storage units to the switch unit in response to the input control signal.

Abstract: A magnetic recording device comprising a magnetic recording medium, a read-write channel for modulating write data, writing it on the magnetic recording medium, reading data from the magnetic recording medium, and demodulating the read data, and a processor for supplying the write data to the read-write channel and being supplied with the read data from the read-write channel. The processor supplies to the read-write channel a microdefect detection pattern having a first pattern for generating a consecutive magnetization inversion during writing and a second pattern for generating, during reading, a signal having a S/N ratio higher than the signal produced by the first pattern, the read-write channel modulates the microdefect detection pattern, writes it to the magnetic recording medium, reads the microdefect detection pattern, which was written, from the magnetic recording medium, and conducts abnormality detection of the microdefect detection pattern, which was read out.

Abstract: A flash memory device includes a flash memory array, a set of non-volatile redundancy registers, a serial interface, and testing logic coupled to the serial interface, the testing logic configured to accept a set of serial commands from an external tester; erase the array; program the array with a test pattern; read the array and compare the results with expected results to identify errors; determine whether the errors can be repaired by substituting a redundant row or column of the array, and if so, generate redundancy information; and program the redundancy information into the non-volatile redundancy registers.

Abstract: Methods of performing a sector erase of flash memory devices incorporating built-in self test circuitry are provided. The present invention employs an interactive verification and sector erase algorithm to verify and repeatedly erase the sector until a portion of the groups of each page of the sector are erased or a first maximum number of erase pulses is achieved. The algorithm further includes a word verification and erase operation that sequentially verifies and erases each word of the sector until each word is erased or a second maximum number of erase pulses is achieved. The second maximum number of erase pulses may be based on a function of the first maximum number of erase pulses. The second maximum number of erase pulses may be input to the sector erase algorithm as a multi-bit code. The second maximum number of erase pulses and conversion of the multi-bit code may be based on a binary multiple of the first maximum number of erase pulses.

Abstract: A test circuit of a semiconductor memory device for performing a test in cooperation with a tester having a plurality of input/output pins connected to a plurality of input/output lines. The test circuit may include a first comparing unit adapted to compare, on a bit-by-bit basis, read data that may be read from memory cells corresponding to an address with expected data, and to output the comparison results as first comparison signals, a second comparing unit adapted to perform a logic operation on the first comparison signals and to generate a flag signal when determining a failure of at least one of the memory cells on the basis of the operation result, and a storage unit adapted to store the first comparison signals in response to the flag signal.

Abstract: Methods, circuits and systems are provided for testing random-access memory (RAM) devices. In one embodiment, one or more test vectors are written to a RAM device. Bit-signals are read from the RAM device one line at a time and are segregated into respective sub-pluralities. Each sub-plurality is tested to determine if there is logical value equality among all of the respective bit-signals. Test signals corresponding to each of the sub-plurality determinations are provided. The test signals are collectively evaluated and an overall equality or non-equality signal is derived.

Abstract: A fuse disposing circuit executes a same test as in a state before a fuse is cut, even in case the fuse is cut. For this, the fuse disposing circuit in accordance with the invention includes a test mode enable confirmation section for informing whether a test mode is enabled; and a fuse set for providing a constant signal by using the output from the test mode enable confirmation section in case of the test mode, regardless of elimination or non-elimination of a fuse.

Abstract: According to embodiments of the present invention, an integrated circuit such as a processor includes a counter to count an actual number of unreliable storage locations in the processor cache, at least one register to store an acceptable number of unreliable storage locations for the cache, a detector to measure a thermal environment of the processor, and circuitry to raise an operating voltage of the processor if the actual number of unreliable storage locations exceeds the acceptable number of unreliable storage locations, and if the thermal environment is acceptable.

Abstract: A BIST circuit device includes a test memory, a test result storage memory having the capacity equal to or larger than the capacity of the test memory, and a control circuit which performs a test for the test memory at an actual application frequency and stores the test result into the test result storage memory.

Abstract: A method for operating a memory that includes a plurality of analog memory cells includes storing data in a first group of the memory cells by writing respective first cell values to the memory cells in the first group. After storing the data, respective second cell values are read from the memory cells in the first group, and differences are found between the respective first and second cell values for each of one or more of the memory cells in the first group. The differences are processed to produce error information, and the error information is stored in a second group of the memory cells.

Abstract: In a circuit for detecting an abnormal operation of memory, an integrated circuit including the same and a method for detecting an abnormal operation, an abnormal operation of memory is detected before an error occurs in the integrated circuit of a micro-computer and the like due to data wrongly output from the memory, enhancing the reliability of the integrated circuit. More specifically, a circuit is provided for detecting an abnormal operation of memory and includes a delay circuit for delaying an output data of memory for a predetermined period of time and for outputting this data as a delay data; and a comparison circuit for outputting a noncoincidence signal in a case that the output data of the memory and the delay data as compared are not coincident with each other.

Abstract: The present disclosure describes embodiments of a compactor for compressing test results in an integrated circuit and methods for using and designing such embodiments. The disclosed compactors can be utilized, for example, as part of any scan-based design. Moreover, any of the disclosed compactors can be designed, simulated, and/or verified in a computer-executed application, such as an electronic-design-automation (“EDA”) software tool. Embodiments of a method for diagnosing faults in the disclosed compactor embodiments are also described.