Patents by Inventor Douglas W. Forehand

Douglas W. Forehand 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: 6385710
    Abstract: In accordance with the present invention, a cache memory subsystem includes a processor, a cache control unit and a SRAM serving as the cache memory. The SRAM is a synchronous SRAM. The cache control unit provides appropriately timed control signals to the SRAM when the processor is accessing the cache memory. The SRAM can be either a pipelined architecture SRAM (register output SRAM) or a flow-through access architecture SRAM (latch output SRAM). The cache control unit is selectably configured to operate in a pipelined mode (1-1-1) or a flow-through (2-2) mode. The cache control unit is configured in the 1-1-1 mode when the SRAM is a pipelined architecture SRAM having a clock rate equal to the processor. When the SRAM is a flow-through architecture SRAM that cannot be clocked at the same rate as the processor, the cache control unit is configured in the 2-2 mode and the SRAM is clocked at a clock rate half of the processor clock rate.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: May 7, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Gary S. Goldman, Christopher Chen, Douglas W. Forehand
  • Patent number: 6195613
    Abstract: A system and method for measuring the equivalent series resistance (ESR) of one or more capacitors using an impedance analyzer, whereby the capacitors are joined to the impedance analyzer with a conductive adhesive. The conductive adhesive may advantageously provide for an electrically and mechanically stable connection between the capacitor and the remainder of the electrical circuit used to measure the ESR of the capacitor. The conductive adhesive may include heat activated or cold solder, or conductive putty. The system comprises a measuring unit for sweeping a frequency range to find the minimum impedance for the capacitor and a connector assembly for holding the capacitor in an electrically and mechanically stable connection using the conductive adhesive. The connector assembly includes a mating portion adapted for electrically connecting the connector assembly to an I/O port of the measuring unit and a terminal portion that accommodates a connection to the capacitor using the conductive adhesive.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: February 27, 2001
    Assignee: Sun Microsystems, Inc.
    Inventors: Tanmoy Roy, Larry D. Smith, Raymond E. Anderson, Thomas J. Pelc, Douglas W. Forehand
  • Patent number: 5847936
    Abstract: A method and structure for routing electrically conductive interconnect paths through a printed circuit board. The printed circuit board includes a plurality of insulating layers and conductive layers, including at least one electrically conductive voltage supply layer for receiving a first supply voltage. A plurality of voltage supply pad patterns are located at the upper surface of the printed circuit board. Each voltage supply pad pattern includes two or more electrically conductive pads which are coupled by one or more electrically conductive traces. Electrically conductive via plugs extend through the printed circuit board to connect the voltage supply layer to the voltage supply pad patterns. Each via plug is connected to one corresponding voltage supply pad pattern, thereby allowing each via plug to provide the first supply voltage to a plurality of pads at the upper surface of the printed circuit board.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: December 8, 1998
    Assignee: Sun Microsystems, Inc.
    Inventors: Douglas W. Forehand, Ray Lamoreaux
  • Patent number: 5831333
    Abstract: A structure and method for controlling the junction temperature of a semiconductor chip in an electronic system. A temperature sensing device and the chip whose junction temperature is to be monitored are located adjacent to one another on the same interconnect structure. A thermally conductive lid can also be attached to the interconnect structure, thereby enclosing the temperature sensing device and the chip within in a closed cavity. Dedicated pins extend from the temperature sensing device through the interconnect structure, for connection to a temperature control circuit. By locating the temperature sensing device on the same interconnect structure as the chip, and within a common enclosure, the temperature sensed by the temperature sensing device is an accurate representation of the actual junction temperature of the chip. By obtaining an improved reading of the actual junction temperature, the operation of the temperature control circuit can be optimized.
    Type: Grant
    Filed: May 14, 1996
    Date of Patent: November 3, 1998
    Assignee: Sun Microsystems, Inc.
    Inventors: Deviprasad Malladi, Douglas W. Forehand
  • Patent number: 5710063
    Abstract: A method of locating a socket on a printed circuit board which includes the steps of fabricating a plurality of pads and one or more fiducials on the upper surface of the printed circuit board, optically aligning a drill with the fiducial, and then drilling a socket hole through the printed circuit board at the location defined by the fiducial. A peg of the socket is inserted into the socket hole to align the socket with the printed circuit board. Alternatively, a method for locating holes on a printed circuit board includes the steps of forming a master tooling hole through the printed circuit board, locating a fiducial on the printed circuit board using the master tooling hole as a guide, focusing on the fiducial with an optically alignable drill, thereby aligning the drill, and then drilling a hole through the printed circuit board using the aligned drill.
    Type: Grant
    Filed: June 6, 1996
    Date of Patent: January 20, 1998
    Assignee: Sun Microsystems, Inc.
    Inventors: Douglas W. Forehand, Karl A. Sauter