Logicvision, Inc.

Siemens Industry Software Gmbh

Northern Telecom Limited

Mentor Graphics Corporation

Other

Logic Visions, Inc.

Benoit Nadeau-Dostie

Jean-François Côté

Jean-Fran&ccedil;ois C&ocirc;t&eacute;

Dwayne M Burek

Jean-Francois Cote

Fadi Maamari

Stephen Kenneth Sunter

Jongsin Yun

Jean-Francedillaois Cote

Vinod K Agarwal

Saman M I Adham

Sonny Ngai San Shum

Jean-Fran&ccedil;ois Cote

Pierre Gauthier

Janusz Rajski

Jerzy Tyszer

Grzegorz Mrugalski

Martin Keim

Sai Vedantam

Robert Abbott

Philip S Wilcox

Bozena Kaminska

Luc Romain

Wei Zou

Allan Silburt

Abu S Hassan

Fidel Muradali

Jean-Francois C&ocirc;t&eacute;

Jean-François Coté

Pierre Gauther

Charles Bernard

Pièrre Gauthier

David P Buck

Eduard Cerny

Harshitha Kodali

Pierre Girouard

Samir Boubezari

Jean-Fran&ccedil;ois Cot&eacute;

Naader Hasani

Dwayne Burek

Vinod Kumar Agarwal

Allan Lloyd Silburt

A testing circuit configured to test and diagnose a read-only memory comprises two multiple-input signature registers configured to generate two sets of signatures for multiple iterations of reading some or all of words stored in the read-only memory, control circuitry configured to control, according to a test algorithm, from which of the outputs of the read-only memory each of the two multiple-input signature registers receives test response signal bits for each of the reading operations during each of the iterations, and a faulty element location determination device configured to generate a faulty element location signal for the read-only memory based on results of comparing the two sets of signatures with reference signatures.

Read-only memory diagnosis and repair

This application discloses a memory built-in self-test system to prompt a memory device to sense values of stored data using a reference trim during memory read operations. The memory built-in self-test system can automatically set the reference trim for the memory device. The memory built-in self-test system includes a memory built-in self-test controller to prompt the memory device to perform the memory read operations with different test values for the reference trim. The memory built-in self-test system also includes a trim feedback circuit to determine when the memory device fails to correctly sense the values of the stored data using the test values for the reference trim, and set the reference trim for the memory device based, at least in part, on the failures of the memory device to correctly sense the stored data.

Memory built-in self-test with automated reference trim feedback for memory sensing

Systems and methods for repairing a memory. A method includes performing a repair analysis of the embedded memories to produce repair information. The method includes storing the repair information in the registers, where the registers are organized into groups having chains of identical length. The method includes performing collision detection between the repair information in each of the groups. The method includes merging the repair information in each of the groups. The method includes repairing the embedded memories using the merged repair information.

Method and apparatus for processing memory repair information

A memory-testing circuit configured to perform a test of reference bits in a memory. In a read operation, outputs of data bit columns are compared with one or more reference bit columns. The memory-testing circuit comprises: a test controller and association adjustment circuitry configurable by the test controller to associate another one or more reference bit columns or one or more data bit columns with the data bit columns in the read operation. The test controller can determine whether the original one or more reference bit columns have a defect based on results from the two different association.

Reference bits test and repair using memory built-in self-test

A circuit comprises: a first clock gating device clocked by a first clock signal and configured to generate first clock pulses when a shift enable signal is active, a first transition detecting device clocked by a second clock signal and configured to generate shift gating pulses when detecting active transitions of the first clock pulses, a second clock gating device clocked by the second clock signal and configured to generate shift clock pulses based on the shift gating pulses to clock second scan elements for a shift operation with first scan elements clocked by the first clock signal, and a first retiming device triggered by active pulse edges of the first clock signal and configurable to hold a value for the shift operation. The circuit may further comprise a delay generating device configured to generate delayed shift gating pulses for generating the shift clock pulses.

Asynchronous interface for transporting test-related data via serial channels

A scan network configured to transport repair information between memories and a controller for a non-volatile storage device comprises: repair registers coupled in parallel to repair information generation circuitry for one of the memories and segment selection devices that divide the repair registers into repair register segments. Each of the segment selection devices comprises: a storage element configured to store a segment selection bit and segment selection bit generation circuitry configured to generate the segment selection bit based on the repair information. Each of the segment selection devices is configurable to include or not include the corresponding repair register segment in a scan path of the scan network in a shift operation based on the segment selection bit.

Configurable built-in self-repair chain for fast repair data loading

A memory-testing circuit configured to perform a test of a memory comprising error-correcting code circuitry comprises repair circuitry configured to allocate a spare row or row block in the memory for a defective row or row block in the memory, a defective row or row block being a row or row block in which a memory word has a number of error bits greater than a preset number, wherein the test of the memory comprises: disabling the error-correcting code circuitry, performing a pre-repair operation, the pre-repair operation comprising: determining whether the memory has one or more defective rows or row blocks, and allocating one or more spare rows or row blocks for the one or more defective rows or row blocks if the one or more spare rows or row blocks are available, and performing a post-repair operation on the repaired memory.

Error-correcting code-assisted memory repair

Aspects of the invention relate to low power BIST-based testing. A low power test generator may comprise a pseudo-random pattern generator unit, a toggle control unit configured to generate toggle control data based on bit sequence data generated by the pseudo-random pattern generator unit, and a hold register unit configured to generate low power test pattern data by replacing, based on the toggle control data received from the toggle control unit, data from some or all of outputs of the pseudo-random pattern generator unit with constant values during various time periods. The low power test generator may further comprise a phase shifter configured to combine bits of the low power test pattern data for driving scan chains.

Test generator for low power built-in self-test

Methods for at-speed testing of a memory interface associated with an embedded memory comprise two write operations in succession, two read operations in succession, and a capture operation using scan cells. The write and read operations are performed during a single clock burst, two separate clock bursts in a clock signal, or two separate clock bursts in separate clock signals.

Methods for at-speed testing of memory interface

A system for repairing embedded memories on an integrated circuit includes an external Built-In Self-repair Register (BISR) associated with every reparable memory. Each BISR is serially configured in a daisy chain with a fuse box controller. The controller determines the daisy chain length upon power up. The controller may perform a corresponding number of shift operations to move repair data between BISRs and a fuse box. Memories can have a parallel or serial repair interface. The BISRs may have a repair analysis facility into which fuse data may be dumped and uploaded to the fuse box or downloaded to repair the memory. Pre-designed circuit blocks provide daisy chain inputs and access ports to effect the system or to bypass the circuit block.

Method and apparatus for storing and distributing memory repair information

A method and a circuit of testing of a memory interface associated with an embedded memory in a semiconductor circuit involves writing to two memory locations in succession; reading the two memory locations in succession in the same order in which the two memory locations were written; capturing output data from the memory interface; and analyzing captured output data to determine whether said captured output data corresponds to expected data.

Method for at-speed testing of memory interface using scan

A clocking method for at-speed scan testing for delay defects in cross-domain paths of interacting synchronous clock domains in a scan circuit, each path originating from a source memory element in one of the domains and terminating at a destination memory element in another of the domains and comprises selectively aligning either a capture edge or a launch edge of the clock of each domain with a corresponding edge of at least one other domain of the interacting synchronous clock domains to determine the cross-domain paths to be tested between a source domain and a destination domain; clocking memory elements in each domain at respective domain clock rates to launch signal transitions from source memory elements in source domains; and for each pair of interacting clock domains under test, capturing, in the destination domain, circuit responses to signal transitions launched along paths originating from the source domain and selectively disabling capturing, in the source domain, of circuit responses to signal transitions launched along paths originating from the destination domain.

Clocking methodology for at-speed testing of scan circuits with synchronous clocks

A method and circuit for collecting memory failure information on-chip and unloading the information in real time while performing a test of memory embedded in a circuit comprises, for each column or row of a memory under test, testing each memory location of the column or row according to a memory test algorithm under control of a first clock, selectively generating a failure summary on-circuit while testing each column or row of the memory; and transferring the failure summary from the circuit under control of a second clock within the time required to test the next column or row, if any, of the memory under test.

Method and circuit for collecting memory failure information

A self-repair circuit for a semiconductor memory provides input and output test selectors coupled to respective data bit group inputs and outputs, respectively and input and output repair selectors coupled between the input and output test selectors and functional inputs and functional outputs, respectively. This arrangement allows all data bit groups to be tested in one pass and all test and repair selector circuitry to be tested.

Memory repair circuit and method

A circuit and a method are provided for testing the enable function of Boundary Scan Register bits that control the driver of unconnected I/O pins of an 1149.1-compliant IC during the IC's reduced pin-count access manufacturing test, and to test the connections to these pins during the test of a circuit board containing the IC, without causing excessive current if a pin is inadvertently short circuited.

Boundary scan with strobed pad driver enable

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Gatineau, Canada

Benoit Nadeau-Dostie