International Business Machines Corporation

Tin-Chee Lo

Jeffrey M Turner

Yuk-Ming Ng

William Vincent Huott

Jay Robert Herring

John D Flanagan

Anil Shrikant Keste

Timothy John Slegel

Louis L Hsu

Li-Kong Wang

Chin-Long Chen

Pradip Patel

Arnold Weinberger

Joseph M Hoke

Sandeep Brahmadathan

Sang Hoo Dhong

John Atkinson Fifield

Frank David Ferraiolo

Howard L Kalter

Brian William Curran

Howard Hao Chen

Timothy Gerard McNamara

Douglas Craig Bossen

William Wu Shen

David Allan Webber

George A Katopis

Matthew A Krygowski

Thomas D Needham

Sanjay Bhikhubhai Patel

Robert M Blake

Shiu K Chan

Frank P Cartman

Paul R Turgeon

Daniele Di Genova

David B Fox

Joseph H Datres, Jr

John Michael Yarolin

Sandy N Luu

Joseph L Braun

Canh Xuan Le

Krishna M Desai

An autonomous error recovery approach is provided for a memory device of a computing system. In response to a request for data, addressed data and associated control information of the memory device are tested for error. If error is detected, the contents of an addressed storage compartment of a second memory device are automatically retrieved and provided responsive to the request. As an example, the memory device may be a cache and the second memory device may be main memory for the computing system.

Method, system and program product for autonomous error recovery for memory devices

A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

On-Chip AC self-test controller

A dynamic arbitration controller includes components for reading current state information as well as records of known arbitration states which may cause a deadlock condition, comparing the current state to the records of known arbitration states and resolving deadlock conditions during arbitration. The dynamic arbitration controller may include circuits for storing and retrieving information related to the arbitration. The dynamic arbitration controller may be implemented as a circuit design or as a computer program product stored on machine readable media.

Apparatus, method and computer program product for dynamic arbitration control

A method and system for performing AC self-test on an integrated circuit that includes a system clock for use during normal operation are provided. The method includes applying a long data capture pulse to a first test register in response to the system clock, applying an at speed data launch pulse to the first test register in response to the system clock, inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register, applying an at speed data capture pulse to a second test register in response to the system clock, inputting the logic path output to the second test register in response to applying the at speed data capture pulse to the second test register, and applying a long data launch pulse to the second test register in response to the system clock.

Method and system for an on-chip AC self-test controller

A method of writing to cache including initiating a write operation to a cache. In a first operational mode, the presence or absence of a write miss is detected and if a write miss is absent, writing data to the cache and if a write miss is present, retrieving the data from a further memory and writing the data to the cache based on least recently used logic. In a second operational mode, the cache is placed in a memory mode and the data is written to the cache based on an address regardless of whether a write miss is present or absent.

Method and system for performing a memory-mode write to cache

A design and method of using a group write slave and a sequence alignment logic module including an identification stage, the identification stage having a first ID input, a second ID input, an ID AND gate, and an ID comparator, a select stage, the select stage having a first select input port, a group write comparator, an individual select comparator, an OR gate and a select AND gate, a Slave Module, wherein the Slave Module includes a group wait signal and a group rearbitrate signal and a sequence alignment logic module which includes a gated logic portion having logic circuitry constructed so as to create a sequence alignment logic module output signal by sequencing and combining the plurality of sequence alignment logic module input signals so as to represent the slowest of the sequence alignment logic module input signals.

Sequence alignment logic for generating output representing the slowest from group write slaves response inputs

A method for performing AC self-test on an integrated circuit, including a system clock for use during normal operation. The method includes applying a long data capture pulse to a first test register in response to the system clock, and further applying at an speed data launch pulse to the first test register in response to the system clock. Inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register. Applying at speed data capture pulse to a second test register in response to the system clock. Inputting the output from the logic path to the second test register in response to applying the at speed data capture pulse to the second register. Applying a long data launch pulse to the second test register in response to the system clock.

A method is disclosed for instructing a computing system to allocate a trace array from an original cache memory, where the method includes dividing the original cache memory into a reduced-size cache memory and a trace array, permitting storage of trace signal data into the trace array, and permitting retrieval of the trace signal data from the trace array.

Method for using a portion of the system cache as a trace array

A system and method for generating random noise for use in testing electronic devices comprises a first random pattern generator circuit for generating first sets of random bit pattern signals; one or more delay devices each receiving a trigger input signal and a random bit pattern signal set for generating in response a respective delay output signal, each delay output signal being delayed in time with respect to a respective trigger signal, a delay time being determined by the bit pattern set received; and, an oscillator circuit device associated with a respective one or more delay devices for receiving a respective delay output signal therefrom and generating a respective oscillating signal, each oscillator signal generated being used to generate artificial random noise for emulating a real noise environment in an electronic device. A second random pattern generator circuit may be provided for generating second sets of random bit pattern signals for receipt by each of the associated oscillator circuit devices in order to frequency adjust in a random manner, each of the oscillator signals.

Digital random noise generator

An exemplary embodiment of the present invention is a method for transmitting data among processors over a plurality of parallel data lines and a clock signal line. A receiver processor receives both data and a clock signal from a sender processor. At the receiver processor a bit of the data is phased aligned with the transmitted clock signal. The phase aligning includes selecting a data phase from a plurality of data phases in a delay chain and then adjusting the selected data phase to compensate for a round-off error. Additional embodiments include a system and storage medium for transmitting data among processors over a plurality of parallel data lines and a clock signal line.

Method and system for selecting data sampling phase for self timed interface logic

Slaves with identification and selection stages for group write

A multi-port memory array is associated with wordlines and bit-lines to perform data read/write operation and has multi-port memory cells each of which includes multiple ports through which the wordlines and bit-lines are provided, multiple transistor devices each of which corresponds to each of the multiple ports and is coupled to a wordline and a bit-line through a corresponding port, each transistor device being gated by a wordline and having a conduction path of which a first end is connected to a bit-line, and a charge storage device commonly connected to a second end of a conduction path of each of the transistor devices, where the charge storage device is charged when any of the plurality of transistor devices is activated. A system for addressing the multi-port memory array includes a conflict detector for detecting a conflict between two or more of the row address signals to generate a conflict control signal corresponding to the conflict detected, a priority logic circuit for performing a logic operation with respect to the request command signals based on a predetermined priority logic to generate prioritized signals, and a selection unit for selecting one of a request command signal and a prioritized signal corresponding to the request command signal in response to the conflict control signal, where a signal selected by the selection unit selects a corresponding one of the row address signals.

Multi-port memory device and system for addressing the multi-port memory device

A method for dynamic bandwidth testing of a link between two computer subsystems useful for determining the amount of data which can be buffered in a transmission line by delay, in which at each end of the line circuit modules are provided to couple the subsystem by a bi-directional multi-bit (BiDi) link, and providing within each said circuit module a built-in circuit and logic for dynamic transmission characterization and test of a said BiDi link between computer subsystems using built-in characterization logic macros, and during a test mode, switching said said built-in circuit and logic to test mode and using the test mode to characterize the link performance, and after the completion of characterization, the switching built-in characterization logic macros back to a normal system mode after programmatically setting timing parameters for the BiDi link to ensure safe operation of data transfer before the BiDi link is switched to system mode.

Method for dynamic bandwidth testing

A fault tolerant circuit having improved error correction and detection properties takes advantage of two distinct forms of information redundancy: modular redundancy and parity check bit redundancy, in a cooperative fashion. In particular, it is shown that simple majority voting logic circuits, when employed in the subject environment, provide an easily realized mechanism for error correction and error detection. This results in an extremely fault tolerant information system.

Fault tolerant system based on voting

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Fishkill, NY, United States of America

Tin-Chee Lo