Patents by Inventor Leland Leslie Day

Leland Leslie Day has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6260164
    Abstract: A functional unit, such as an SRAM, in a single clock chip design that contains a scan path can be clocked on either rising edge and falling edge of the clock. The functional unit includes a clock signal having two phases and a plurality of latches for scanning. Two scan latches are added outside the array of the functional unit. In one clock phase, the two scan latches form a latch pair which is connected to the array at Scan-in side. In the other clock phase, one scan latch is connected to the array at the Scan-in side, and the other scan latch is connected to the array at the Scan-out side. In scan/hold operations, a first control signal for the array which is clocked at the falling edge of the clock leads a second control signal for the array which is clocked at the rising edge of the clock. In ABIST/functional operations, the first control signal for the array which is clocked at the falling edge of the clock trails the second control signal for the array which is clocked at the rising edge of the clock.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: July 10, 2001
    Assignee: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Leland Leslie Day, Paul Allen Ganfield, Charles Luther Johnson
  • Patent number: 6178534
    Abstract: A system and method for conducting a repeatable logic test on at least one functional unit of an IC chip includes steps of selecting at least one functional unit of at least several functional units, propagating test data through a part or all functional units of the time domain; and capturing test data of the selected functional unit. The functional units are either selected or held inactive such that only the selected functional unit is allowed to capture the test results for determining a critical timing path within the selected functional unit and only the functional unit. By selecting different combination of the functional unit(s), a number of the critical timing paths are readily determined in the chip.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: January 23, 2001
    Assignee: International Business Machines Corporation
    Inventors: Leland Leslie Day, Paul Allen Ganfield
  • Patent number: 6158032
    Abstract: A data processing system, circuit arrangement, program product, and method thereof utilize a multi-path scan interface that is capable of providing multiple scan paths into a plurality of scan ring segments in an integrated circuit device. The multi-path scan interface utilizes one or more multiplexers coupled between scan in and scan out ports and at least one scan ring segment to provide alternate scan paths depending upon select signals supplied to each multiplexer. With such a configuration, a standardized scan interface may developed for interfacing with a wide variety of scan ring segments, and optionally, for multiple purposes. As a result, the amount of custom circuitry necessary to provide access to scan ring segments is significantly reduced.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: December 5, 2000
    Assignee: International Business Machines Corporation
    Inventors: Guy Richard Currier, Leland Leslie Day, Steven Michael Douskey, Paul Allen Ganfield, James Maurice Wallin
  • Patent number: 5835502
    Abstract: A method and apparatus for handling variable data word widths and array depths in an array built-in self-test system for testing a plurality of memory arrays using a single controller. Each array includes a predetermined row and column address depth and data word width. Each array further includes a scan register. A universal test data word is generated and sent to the scan register of each array. The universal length test data word has a length dependent upon the maximum row address depth, maximum column address depth and/or the maximum data word width. A portion of the test data word which exceeds the column address depth, row address depth and/or the data word width of a particular array is shifted off the end of the scan register of the particular array.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: November 10, 1998
    Assignee: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen, Leland Leslie Day, Paul Allen Ganfield, Murali Vaddigiri, Paul Wong
  • Patent number: 5663966
    Abstract: A system and method for reducing simultaneous switching during scan-based testing of a system logic design. System logic is divided into clusters of system logic, and one or more scan chains are associated with each logic cluster. Each of the logic clusters are concurrently scan tested, yet circuitry in the scan chains associated with a cluster are triggered at different times than the circuitry in the scan chains of other clusters. Offset scan control signals provide the triggering for the scan chains of different clusters. Release and capture functions are also controlled to reduce simultaneous release and capture switching in different clusters.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: September 2, 1997
    Assignee: International Business Machines Corporation
    Inventors: Leland Leslie Day, Steven Michael Douskey, Paul Allen Ganfield