Patents Represented by Attorney Michael A. Davis
  • Patent number: 5548738
    Abstract: A processing system and method of operation are provided. Multiple instructions are dispatched in a sequence to execution circuitry for execution. For each instruction, a determination is made in advance of execution about whether an exception is possible to result from execution of the instruction. An instruction is completed in response to determining an exception does not result from execution of the instruction and of each instruction preceding the instruction in the sequence, independent of whether the execution circuitry has finished execution of each instruction for which an exception is not possible.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 20, 1996
    Assignee: International Business Machines Corporation
    Inventor: Seungyoon P. Song
  • Patent number: 5546599
    Abstract: A processing system and method of operation are provided. A determination is made about whether to dispatch an instruction to execution circuitry for execution. After determining to dispatch the instruction, a determination is made about whether an exception condition exists for the instruction. The instruction is dispatched to the execution circuitry. In response to determining an exception condition exists for the instruction, an indication is output to inhibit execution of the instruction by the execution circuitry.
    Type: Grant
    Filed: March 31, 1994
    Date of Patent: August 13, 1996
    Assignee: International Business Machines Corporation
    Inventor: Seungyoon P. Song
  • Patent number: 5544342
    Abstract: A method and system are provided for prefetching information in a processing system. A first memory has multiple first locations. At least one of the first locations stores information including an address of a different first location, the different first location having been referenced in the first memory after a previous reference to the one first location. A second memory has at least one second location storing information from the one first location, including the address. Information is prefetched to the second memory from the address of the first memory, in response to a reference to the second location.
    Type: Grant
    Filed: July 10, 1995
    Date of Patent: August 6, 1996
    Assignee: International Business Machines Corporation
    Inventor: Mark E. Dean
  • Patent number: 5539681
    Abstract: A method and circuitry are provided, in which a first operation is performed with first circuitry. A second operation is performed with second circuitry. A first signal is generated in response to the first operation. A second signal is generated in response to the second operation. Power consumption is adjusted within the second circuitry in response to the first and second signals.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: July 23, 1996
    Assignees: International Business Machines Corporation, Motorola Inc.
    Inventors: Michael C. Alexander, Arturo L. Arizpe, Gianfranco Gerosa, James A. Kahle, Aubrey D. Ogden
  • Patent number: 5528744
    Abstract: A data processing system is provided. The system includes a window based display for displaying display windows. A processor executes multiple interleaved data processing tasks. The processor is able to trigger execution of a second task by the processor in response to execution of a first task by the processor The first and second tasks are associated with one or more of the display windows. The processor controls display of the associated display windows on the display. If the processor triggers execution of the second task in response to execution of the first task, the processor controls display of the second task's display window(s) to be visually connected to and move with the first task's display window(s) in response to data identifying the first task's display window(s).
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: June 18, 1996
    Assignee: International Business Machines Corporation
    Inventor: Matthew K. Vaughton
  • Patent number: 5524224
    Abstract: A processing system and method of operation are provided, In response to a branch instruction, a first instruction is processed so that a storage location is associated with the first instruction prior to execution of the branch instruction. In response to execution of the branch instruction, a second instruction is processed independent of information previously stored in the storage location so that the storage location is associated with the second instruction prior to completion of the branch instruction.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: June 4, 1996
    Assignees: International Business Machines Corporation, Motorola, Inc.
    Inventors: Marvin A. Denman, Artie A. Pennington, Seungyoon P Song
  • Patent number: 5517441
    Abstract: Content addressable memory circuitry and a method of operation are provided. First information is stored. A logic state of a first match line is selectively modified in response to a comparison between the first information and second information. Also, third information is stored. A logic state of a second match line is selectively modified in response to a comparison between the third information and fourth information. A logic state of the second match line is selectively modified in response to the logic state of the first match line.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: May 14, 1996
    Assignee: International Business Machines Corporation
    Inventors: Carl D. Dietz, Kathryn J. Hoover
  • Patent number: 5491653
    Abstract: A Carry-Save Adder circuit having differential signal response and output is provided. The circuit includes a pair of cross-coupled transistors powered by an upper voltage rail. The output of a first transistor of the pair of cross-coupled transistors is connected to the output of a first precharge transistor that is powered by the upper rail and controlled by a clock. The output of a second transistor of the pair of cross-coupled transistors is connected to the output of a second precharge transistor that is powered by the upper rail and controlled by the clock. A logic circuit is wired to perform a logical function, either a Sum or a Carry function, and has a plurality of inputs, an output, and a complementary output. The output of the logic circuit is connected to the output of the first transistor of the pair of cross-coupled transistors, and the complementary output is connected to the output of the second transistor of the pair of cross-coupled transistors.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: February 13, 1996
    Assignee: International Business Machines Corporation
    Inventors: Michael P. Taborn, Paul K. Miller
  • Patent number: 5491829
    Abstract: A method and system for enhanced instruction dispatch efficiency in a superscalar processor system having a plurality of intermediate storage buffers, a plurality of general purpose registers, and a storage buffer index. Multiple scalar instructions may be simultaneously dispatched from a dispatch buffer to a plurality of execution units. Each of the multiple scalar instructions generally include at least one source operand and one destination operand. A particular one of the plurality of intermediate storage buffers is assigned to a destination operand within a selected one of the multiple scalar instructions. A relationship between the particular one of the plurality of intermediate storage buffers and a designated one of the plurality of general purpose registers is stored in the storage buffer index at that time when the instruction which has been dispatched is replaced in the dispatcher by another instruction in the application program sequence.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: February 13, 1996
    Assignee: International Business Machines Corporation
    Inventors: Chin-Cheng Kau, Aubrey D. Ogden, Donald E. Waldecker
  • Patent number: 5471599
    Abstract: A computer memory system having partitioned page address for instructions and operands. The partitioning scheme for the virtual addressing memory minimizes the delay between the translation logic and the page translation RAMs. Computer processor performance is delayed by only a single clock cycle by the sharing of the memory address bus control between two address processors.
    Type: Grant
    Filed: April 18, 1994
    Date of Patent: November 28, 1995
    Assignee: International Business Machines Corporation
    Inventors: Timothy B. Brodnax, Bryan K. Bullis, Steven A. King, Dale A. Rickard
  • Patent number: 5471189
    Abstract: Comparator circuitry and a method of operation are provided. First and second match lines are precharged. First and second information are compared, and the first match line is selectively discharged in response thereto. Third and fourth information are compared, and the second match line is selectively discharged in response thereto. The second match line is discharged in response to discharging the first match line.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: November 28, 1995
    Assignee: International Business Machines Corp.
    Inventors: Carl D. Dietz, Kathryn J. Hoover
  • Patent number: 5465373
    Abstract: A method and system for permitting single cycle instruction dispatch in a superscalar processor system which dispatches multiple instructions simultaneously to a group of execution units for execution and placement of results thereof within specified general purpose registers. Each instruction generally includes at least one source operand and one destination operand. A plurality of intermediate storage buffers are provided and each time an instruction is dispatched to an available execution unit, a particular one of the intermediate storage buffers is assigned to any destination operand within the dispatched instruction, permitting the instruction to be dispatched within a single cycle by eliminating any requirement for determining and selecting the specified general purpose register or a designated alternate general purpose register.
    Type: Grant
    Filed: January 8, 1993
    Date of Patent: November 7, 1995
    Assignee: International Business Machines Corporation
    Inventors: James A. Kahle, Chin-Cheng Kau, David S. Levitan, Aubrey D. Ogden, Ali A. Poursepanj, Paul K.-G. Tu, Donald E. Waldecker
  • Patent number: 5442766
    Abstract: A method and system for distributed instruction address translation in a multiscalar data processing system having multiple processor units for executing multiple tasks, instructions and data stored within memory at real addresses therein and a fetcher unit for fetching and dispatching instructions to the processor units. A memory management unit (MMU) is established which includes a translation buffer and translation algorithms for implementing page table and address block type translations of every effective address within the data processing system into real addresses within memory. A translation array, which includes a small number of translation objects for translating effective addresses into real addresses, is then established within the fetcher unit. The translation objects are periodically and selectively varied, utilizing the translation capability of the memory management unit (MMU), in response to a failure to translate an effective address into a real address within the fetcher unit.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: August 15, 1995
    Assignee: International Business Machines Corporation
    Inventors: Tan V. Chu, Charles R. Moore, John S. Muhich, Terence M. Potter
  • Patent number: 5437017
    Abstract: Translation lookaside buffers (TLB) are often utilized in the data processing system to efficiently translate an effective or virtual address to a real address within system memory. In systems which include multiple processors which may all access system memory, each processor may include a translation lookaside buffer (TLB) for translating effective addresses to real addresses and coherency between all translation lookaside buffers (TLB) must therefore be maintained. The method and system disclosed herein may be utilized to broadcast a unique bus structure in response to an execution of a translation lookaside buffer invalidate (TLBI) instruction by any processor within a multiprocessor system. The bus structure is accepted by other processors along the bus only in response to an absence of a pending translation lookaside buffer invalidate (TLBI) instruction within each processor.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: July 25, 1995
    Assignee: International Business Machines Corporation
    Inventors: Charles R. Moore, John S. Muhich
  • Patent number: 5421020
    Abstract: A data processing system for speculatively executing instructions. The data processing system includes a memory for storing instructions at addresses which can be generated by a branch unit in a processor. The processor also has a count register for storing an update value, a dispatch version value and a completion version value. A fetcher connected to the branch unit fetches instructions from memory based upon addresses calculated by the branch unit. The branch unit handles processing of conditional branch instructions. To do so, means for initializing the update value and the dispatch version value for branch control are provided. Further included are means responsive to completion of initialization for copying the update value as the completion version value. The system further includes means responsive to dispatch of a conditional branch instruction for examining the dispatch version value to determine if a branch should be taken and then decrementing the dispatch version value.
    Type: Grant
    Filed: January 8, 1993
    Date of Patent: May 30, 1995
    Assignee: International Business Machines Corporation
    Inventor: David S. Levitan
  • Patent number: 5420808
    Abstract: A method and circuitry are provided, in which a first operation is performed with first circuitry. A second operation is performed with second circuitry. A first signal is generated in response to the first operation. A second signal is generated in response to the second operation. Power consumption is adjusted within the second circuitry in response to the first and second signals.
    Type: Grant
    Filed: May 13, 1993
    Date of Patent: May 30, 1995
    Assignees: International Business Machines Corporation, Motorola, Inc.
    Inventors: Michael C. Alexander, Arturo L. Arizpe, Gianfranco Gerosa, James A. Kahle, Aubrey D. Ogden
  • Patent number: 5413321
    Abstract: A method and system are provided for operating a document assembly system. Assembly is initiated of a set of documents in a sequence. Improper assembly is detected of a particular one of the documents. Assembly is reinitiated of a replacement for the particular document after each preceding document in the sequence of the set is no longer being assembled by the document assembly system. In another embodiment, improper assembly of particular documents is detected and stored in memory, the stored indications are sorted according to the original sequence, and assembly of replacements for the particular documents is reinitiated according to the sequence.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: May 9, 1995
    Assignee: International Business Machines Corporation
    Inventors: Jon M. Banks, Melvin R. Clearman, Jr., James C. Colson, David O. Craig, David C. Loose, James E. Varan
  • Patent number: 5410657
    Abstract: A method and system are disclosed for implementing floating point exception enabled operation without substantial performance degradation. In a multiscalar processor system, multiple instructions may be issued and executed simultaneously utilizing multiple independent functional units. This is typically accomplished utilizing separate branch, fixed point and floating point processor units. Floating point arithmetic instructions within the floating point processor unit may initiate one of a variety of exceptions associated within invalid operations and as a result of the pipelined nature of floating point processor units an identification of which instruction initiated the exception is not possible. In the described method and system, an associated dummy instruction having a retained instruction address is dispatched to the fixed point processor unit each time a floating point arithmetic instruction is dispatched to the floating point processor unit.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: April 25, 1995
    Assignee: International Business Machines Corporation
    Inventors: Christopher H. Olson, Terence M. Potter
  • Patent number: 5363495
    Abstract: A data processing system is provided that includes a plurality of execution units each including independent circuits for storing and executing instructions. A circuit is also included for providing instructions from a sequence of instructions to the execution units where each instruction is provided to only one of the execution units. The system includes a circuit for detecting when an instruction in a first execution unit must complete execution prior to execution of an instruction in a second execution unit to produce correct results. A circuit is further included, responsive to the circuit for detecting, for delaying executing the instruction in the second execution unit until the instruction in the first execution unit has completed execution.
    Type: Grant
    Filed: August 26, 1991
    Date of Patent: November 8, 1994
    Assignee: International Business Machines Corporation
    Inventors: Richard E. Fry, Troy N. Hicks
  • Patent number: 5326087
    Abstract: A method and system are provided for calibrating a document assembly system. An operation is initiated of a document assembly line of the document assembly system. During the operation, an activation is sensed of an activation element along the document assembly line. In response to the activation, positional information is determined for relating the activation element to the document assembly line.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: July 5, 1994
    Assignee: Internationaal Business Machines Corporation
    Inventors: James C. Colson, David O. Craig, David C. Loose