International Business Machines Corporation

Thomas J Knips

Donald W Plass

William Vincent Huott

James W Dawson

John D Davis

Kenneth J Reyer

Tom Y Chang

Paul Alan Bunce

Uma Srinivasan

Matthew Steven Hyde

K Paul Muller

Gregory J Fredeman

Kevin W Kark

Pradip Patel

Daniel Rodko

Luiz Carlos Alves

Douglas J Malone

William J Clarke

Christopher Raymond Conklin

Joseph E Eckelman

Patrick James Meaney

Phong T Tran

Donato Orazio Forlenza

Gary William Maier

Orazio Pasquale Forlenza

William James Hurley

Bryan L Mechtly

Thomas E Miller

David J Lund

A method for testing a circuit includes performing, by a test engine, a test of bit write to a memory. The test includes defining a bit group based on a set of bits from an address of a memory location. The test further includes generating a bit mask for the bit group. The test further includes performing a bit write operation to the address to store a sequence of bits, the sequence of bits selected using a predetermined bit pattern. The test further includes reading content of the address. The test also includes comparing, using the bit mask, only bits corresponding to the bit group from the sequence of bits and from the content of the address.

Testing bit write operation to a memory array in integrated circuits

A computer-implemented method includes receiving a memory address of a memory location in a memory that has been identified to be failing. The method further includes determining that the memory location is from a particular portion of the memory. The method further includes, in response to a number of memory locations that are identified to be failing from the particular portion of the memory being below a predetermined threshold, logging the memory address in a set of failing address registers associated with the memory, otherwise, skipping the logging of the memory address in the failing address registers.

Failing address registers for built-in self tests

A method for testing a circuit includes performing, by a test engine, a test of a memory element of the circuit, the test accesses a memory location in the memory element, the memory location is identified by an address, and the memory location is accessed via a first port associated with a first port select bit. The method further includes, in response to detecting a failure associated with the memory location, determining an existing entry for the address in a failed address register, and determining that the existing entry in the failed address register is associated with a second port select bit, distinct from the first port select bit. The method further includes, in response to the second port select bit being distinct from the first port select bit, setting a multi-port failure flag for the memory element that is being tested.

Testing multi-port array in integrated circuits

Aspects of present disclosure relate to an integrated circuit chip (chip), a method and a computer program product of testing the chip. The method of testing the chip may include: partitioning the chip into various partitions, loading built-in self-test (BIST) test instructions into BIST engine and initializing a current partition counter, performing BIST test on current partition, transmitting test results of the current partition of the chip to an external test data storage, checking whether current partition is the last partition, incrementing current partition counter, and returning to performing BIST on a next partition when current partition is not the last partition, and exiting BIST test when current partition is the last partition. The test results may be stored in one or more inactive storage elements of the chip. The number of partitions may include: one partition, a predetermined number of partitions, and a variable number of partitions.

Partition-able storage of test results using inactive storage elements

Embodiments relate to built-in testing of an unused element on a chip. An aspect includes concurrently performing on a chip comprising a plurality of chip elements comprising a plurality of active elements, each active element enabled to perform a respective function, and at least one unused element that is disabled from performing the respective function and configured to be selectively enabled as an active element, the respective functions of the respective active elements and a built-in self test (BIST) test of the at least one unused element. Another aspect includes inputting an input test pattern to the unused element. Another aspect includes receiving an output test pattern based on the input test pattern from the unused element. Another aspect includes comparing the input test pattern to the output test pattern. Another aspect includes determining whether the unused element passed or failed the testing based on the comparison.

Built-in testing of unused element on chip

A method for implementing at speed bit fail mapping of an embedded memory system having ABIST (Array Built In Self Testing), comprises using a high speed multiplied clock which is a multiple of an external clock of an external tester to sequence ABIST bit fail testing of the embedded memory system. Collect store fail data during ABIST testing of the embedded memory system. Perform a predetermined number of ABIST runs before issuing a bypass order substituting the external clock for the high speed multiplied clock. Use the external clock of the tester to read bit fail data out to the external tester.

AC ABIST diagnostic method, apparatus and program product

Memory array built in self testing utilizing including a simple data history table. The table is used to track failing locations observed during any level of assembly test of processor or logic semiconductor chips where the chips contain SRAM macros with redundant elements for failure relief.

Efficient memory product for test and soft repair of SRAM with redundancy

An apparatus and method for protecting a computer system from array reliability failures uses Array Built-In Self-Test logic along with code and hardware to delete cache lines or sets that are defective, identify corresponding fuse repair values, proactively call home if spare fuses are not available, schedule soft fuse repairs for the next system restart, schedule line deletes at the next restart, store delete and fuse repairs in a table (tagged with electronic serial id, timestamp of delete or ABIST fail event, address, and type of failure) and proactively call home if there were any missed deletes that were not logged. Fuse information can also be more permanently stored into hardware electronic fuses and/or EPROMs. During a restart, previous repairs are able to be applied to the machine so that ABIST will run successfully and previous deletes to be maintained with checking to allow some ABIST failures which are protected by the line deletes to pass.

Method for self-correcting cache using line delete, data logging, and fuse repair correction

Efficient method of test and soft repair of SRAM with redundancy

A method and apparatus for implementing ABIST data compression and serialization for memory built-in self test of SRAM with redundancy. The method includes providing detection signals asserted for one failing data out, two failing data outs, and greater than two failing data outs. The method also includes individually encoding the failing bit position of each corresponding failing data out with a binary representation value corresponding therewith. The method further includes serializing results of the providing detection signals and the individually encoding, and transmitting results of the serializing to a redundancy support register function on a single fail buss.

ABIST data compression and serialization for memory built-in self test of SRAM with redundancy

A method and apparatus for providing flexible modular redundancy allocation for memory built in self test of random access memory with redundancy. The apparatus includes a first redundancy support register that includes inputs for receiving an address of a location in memory under test and data relating to must fix repair elements. The address includes a row and column vector of the location. The first redundancy support register also includes outputs for transmitting the address and data. The apparatus also includes a second redundancy support register including inputs for receiving the address and data from the outputs of the first redundancy support register. Each of the inputs of the second redundancy support register shares a one-to-one correspondence to each of the outputs of the first redundancy support register. The apparatus further includes allocation logic for providing a modular implementation of the first redundancy support register and the second redundancy support register.

Method and apparatus for providing flexible modular redundancy allocation for memory built in self test of SRAM with redundancy

ABIST apparatus with integrated directory compare logic functionality, and ABIST error detection functionality. The apparatus includes two subsystems NOR'ed together. The first subsystem is for bit-wise logically ANDing corresponding array valid bits and tag valid inputs, generating '0' for a match and '1' for a mis-match, and logically ORing the bit-wise result to generate a &#x201c;1&#x201d; hit if there are any bit-wise mismatches. The second subsystem further receives ABIST control logic as an input to either: (a). combine array valid bits tag valid inputs to produce valid output, or (b) compare array valid bits with tag valid inputs. The apparatus further includes logical NOR functionality for the outputs of the first and second subsystems.

Integrated system logic and ABIST data compression for an SRAM directory

A decoder circuit includes a pulse powered stage having a plurality of fan-in inputs thereto, a dynamic stage fed by the pulse powered stage, and a replica node selectively coupled to an output node of the pulse powered stage by a pass device. The pass device and the dynamic stage are controlled by a clock signal so as to enable a self-timed evaluation of the pulse-powered stage with a clocked enablement of the dynamic stage. A pull up device restores the dynamic stage to a precharged condition, the pull up device controlled by a second clock signal independent of the first clock signal.

Fast pulse powered NOR decode apparatus with pulse stretching and redundancy steering

A method for real time capture of the desired failing chip cell diagnostic information from high speed testing of a semiconductor chip with on chip LSSD registers having built in self test functions and a fail trap register, and there is provided a programmable skip fail counter, and a hold and compare function circuit. The programmable skip counter is enabled for initialization to a 'record first fail' mode, and then with non-zero values of the skip counter to a 'record next fail' mode with scan initialization of the LSSD registers of the semiconductor chip. The diagnostic information for the chip is obtained by collecting data from scanning the circuits of said semiconductor chip for a failing cell for immediate scan-out off-chip at a level of assembly test.

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Wappingers Falls, NY, United States of America

Thomas J Knips