Lucent Technologies Inc.

Agere Systems Guardian Corp.

At+t Corp.

Other

Ilyoung Kim

Yervant Zorian

Frank P Higgins

James Louis Lewandowski

Paul William Rutkowski

Larry Ray Fenstermaker

Hai Quang Pham

Jeffrey Jay Nagy

Miroslaw Guzinski

Goh Komoriya

A reconfiguration memory device is provided associated with a main memory array. The reconfiguration memory device generates a spare address in real time corresponding to a faulty address. The reconfiguration memory device is coupled to an address line, so that when address information is received for the main memory array, the address information is also received by the reconfiguration memory device. The reconfiguration memory device is adapted to send an output signal that results in the address in the spare memory address array being addressed, if the received address information corresponds to a stored faulty address. The output signal includes a spare control signal that directs components to look to the output of the spare memory.

Built-in self-test and self-repair methods and devices for computer memories comprising a reconfiguration memory device

A method is provided for determining the location of faulty components in a computer memory array on a chip and for providing a software repair procedure. According to the method, the location of faulty components in a computer memory array is determined by successively reading and writing to locations in the array according to an algorithm. If a faulty component is detected, it is determined whether a spare component in a spare memory array on the chip is available. If a spare component is available, a spare component is designated to correspond to the faulty component. A look up table on the same chip stores information representing the location of the faulty component associated with information representing the location of the corresponding spare component. The method may also include, testing the memory array by successively reading and writing to locations on the memory array according to an algorithm, during which step, when a faulty component with which a spare component is associated is addressed, the look up table is used to identify the spare component corresponding to the faulty component, and the spare component is addressed.

System and method for detecting faults in computer memories using a look up table

This invention relates to a token passing network, called a Universal BIST Scheduler (UBS), and a method for scheduling BISTed memory elements based on: executing BIST in multiple stages in order to optimize the efficiency of continuous processing and to apply a single waiting period to multiple SBRIC_RSs where, for example, BIST includes retention testing; dividing resource controllers or SBRIC_RSs corresponding to one or more RSB elements into a matrix such that each SBRIC_RS executes the BIST of its memory elements concurrently and/or successively depending on the SBRIC_RS's position in the matrix; and passing a token to initiate processing of a set of SBRIC_RSs in the matrix through a level signal rather than a pulse signal in order to ensure that the signal is not lost.

Built-in self-test controlled by a token network and method

A memory device has first and second sets of memory cells. Each of the cells in the second set is a neighboring cell corresponding to a respective cell of the first set. A data generating function generates a first pattern and a second pattern. A controller causes the first pattern to be written in the first set of memory cells, causes each cell in the second set of memory cells to be read simultaneously while the corresponding neighboring cell in the first set of memory cells is being written to, and causes a datum to be read from each cell in the second set of memory cells after the corresponding neighboring cell in the first set of memory cells is written to. An output data evaluator determines whether the data read from the second set of memory cells match the second pattern, and detects a fault in the memory device, if the data read do not match the second pattern.

Method and system for testing multiport memories

A method and apparatus are described for detecting an optimized set of predetermined faults in a memory device which ensure an acceptable quality level. The method and apparatus comprise a BIST March algorithm optimized to accelerate the testing time by reducing the number of read/write operations necessary to detect a set of predetermined faults.

Optimized built-in self-test method and apparatus for random access memories

Memory test hardware is provided for generating signals for testing a first memory array and a second memory array. The first memory array and the second memory array may be any two of main memory array, a spare memory array, and reconfiguration memory array, or the apparatus may be adapted for testing all three memory arrays. The memory test hardware may include a controller for generating control signals, a data generator coupled to the controller for generating data signals, and an address generator coupled to the controller for generating address signals. The test device may further include an output data evaluator and repair unit for receiving signals from the main memory array and the spare memory array and for detecting faults in those arrays.

Apparatus for detecting faults in multiple computer memories

A variety of FIFOs, including single and dual port, RAM-type and/or having a ring-type addressing mechanism, are tested by causing the FIFOs to execute a test method comprised of a series of steps. Upon execution, the steps cause the FIFO to manifest a variety of faults. This test method manifests faults by monitoring the outcome of operations and the values of particular flags indicative of normal FIFO operation.

Testing method and apparatus for first-in first-out memories

This invention relates to a token passing network, called a Universal BIST Scheduler (UBS), and a method for scheduling BISTed memory elements based on: executing BIST in multiple stages in order to optimize the efficiency of continuous processing and to apply a single waiting period to multiple SBRIC.sub.-- RSs where, for example, BIST includes retention testing; dividing resource controllers or SBRIC.sub.-- RSs corresponding to one or more RSB elements into a matrix such that each SBRIC.sub.-- RS executes the BIST of its memory elements concurrently and/or successively depending on the SBRIC.sub.-- RS's position in the matrix; and passing a token to initiate processing of a set of SBRIC.sub.-- RSs in the matrix through a level signal rather than a pulse signal in order to ensure that the signal is not lost.

Built-in self-test in a plurality of stages controlled by a token

A dual-port RAM-type ring-address FIFO including a data input register with a set of transparent latches is tested by causing the FIFO to execute a test method comprised of a set of interwoven steps. Upon execution, the steps of the method cause the FIFO to manifest all possible memory, address and functional faults. This test method manifests faults by causing the FIFO to alter the state of various flags it normally sets and by altering the logic state of the data normally produced by the FIFO.

Method for built-in self-testing of ring-address FIFOs having a data

An N stage counter includes peripheral circuitry for testing the operability of the counter. The peripheral circuitry includes gating means coupled between certain stages of the counter for partitioning the counter into at least first and second counter sections during a testing mode. During the testing mode, the N counter stages are reset to an all zero condition and this resettability capability is detected. During the testing mode, the N counter stages are also set to a predetermined value and the settability of the counter stage to a non-zero condition is also detected. During one phase of the testing mode, the first section counts a predetermined number of clock cycles while all counts produced at the outputs of all the stages of the second section are totalled in a register means. During another phase of the testing mode, the second section counts a predetermined number of clock cycles while all the counts produced at the outputs of all the stages in the first section are totalled in the register means. Thus, during the one phase, the first section functions as a timer for the second section and during the second phase, the second section functions as a timer for the first section. The counts generated by the first and second sections are subsequently totalled and compared with a predetermined number to ascertain the operability of the counter.

Method and apparatus for testing large embedded counters

An address count which increases up to, or decreases down from, a user-selected value is generated by a non-fully-decoded address generator (10) which is configured of a plurality of interconnected, sequentially-actuated of bit generators (12'.sub.1 -12'.sub.k), each generating a separate one of the bits of the address count. Each of the bit generators is presettable to at least one logic state, with at least one bit generator being presettable to a separate one of two logic states. A control circuit (30' presets the bit generators in accordance to the user-selected initial value so that when the bit generators are sequentially actuated, their collective count runs up to, or down from, the seed value.

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Plainsboro, NJ, United States of America

Ilyoung Kim