Patents by Inventor James Norris Dieffenderfer

James Norris Dieffenderfer 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: 6330296
    Abstract: The present invention provides a delay-locked loop (DLL). The DLL comprises a phase-frequency detector (PFD) for receiving a reference signal. The DLL further includes a charge pump which is coupled to the PFD. The DLL also includes a loop filter which is coupled to the charge pump and the PFD. Additionally in the DLL, delay line means is coupled to the charge pump and the loop filter. The delay line means provides a feedback signal to the PFD. The DLL further includes monitor means coupled to the PFD, the charge pump and the loop filter. The monitor means is for detecting when a voltage across the loop filter is at a predetermined level, wherein when the voltage is at the predetermined level the monitor means causes the PFD to enter a pump-down mode until the feedback signal is aligned with the reference signal. An advantage of the present invention is that DLL loop tracking failures based upon a stuck condition are reliably avoided.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: December 11, 2001
    Assignee: International Business Machines Corporation
    Inventors: Francois Ibrahim Atallah, George Diniz, James Norris Dieffenderfer, David John Seman
  • Patent number: 6192486
    Abstract: The present invention provides a method and system for bypassing defective sections with a memory array of a computer chip. The circuit in accordance with the present invention includes a register for controlling the effective size of the memory array based upon the detection of at least one defective section in the memory array, and a multiplexer for receiving an index address for the memory array and for the mapping of the index address based upon the register means. The circuit in accordance with the present invention does not use fuses to conduct repairs and thus does not require additional area on the chip for such fuses. As such, it eliminates the complications in the manufacturing process related to fuses and redundant cells. The circuit in accordance with the present invention dynamically manipulates the address of the array to bypass the defective regions of the array.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: February 20, 2001
    Assignee: International Business Machines Corporation
    Inventors: Anthony Correale, Jr., James Norris Dieffenderfer, William Robert Lee, Trevor Scott Garner
  • Patent number: 6001662
    Abstract: A method and system for manufacturing integrated circuit devices having multiple memory units embedded therein. Initially, a single reusable configurable test circuit is fabricated within an integrated circuit device. A number and type of each memory unit embedded within the integrated circuit device are then identified. Finally, the single reusable configurable test circuit is configured, in response to the identifying of a number and type of each memory unit, such that only one test circuit is required for use with multiple integrated circuit devices having multiple diverse memory units embedded therein. The single reusable configurable test circuit can be placed within or outside a fixed core of the integrated circuit device. In addition, the single reusable configurable test circuit can include array built-in self test (ABIST) controller which includes a hierarchical memory configuration that includes a state machine, address counter, compare register and data pattern generator.
    Type: Grant
    Filed: December 2, 1997
    Date of Patent: December 14, 1999
    Assignee: International Business Machines Corporation
    Inventors: Anthony Correale, Jr., James Norris Dieffenderfer, Trevor Scott Garner, Ronald William Kohake, Ketan Vitthal Patel
  • Patent number: 5708852
    Abstract: A serial port having a pattern generation mode and a microprocessor using same. The serial port uses a transmit circuit controlled by a state machine which determines whether start and stop bits are transmitted by a computer implemented method. In pattern generation mode, start and stop bits are not transmitted, and the serial port lends itself to transmitting pulse width modulation data. In one embodiment, the serial port is used in a microprocessor which includes a central processing unit (CPU) and a bus interface unit.
    Type: Grant
    Filed: August 1, 1995
    Date of Patent: January 13, 1998
    Assignee: International Business Machines Corporation
    Inventors: Donna Wiltsey Aebli, James Norris Dieffenderfer