Patents by Inventor Frederick R. Keller

Frederick R. Keller 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: 5293597
    Abstract: A memory management arrangement facilitates interprocess data transfers by eliminating the need to construct temporary mapping tables when performing the data transfer operation. The arrangement includes the use of multiple and concurrent mapping tables in conjunction with the transmission of mapping table indentification bits with each data transfer operation.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: March 8, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Craig W. Jensen, Frederick R. Keller
  • Patent number: 4914580
    Abstract: A communication system includes a processor, memory circuits and a plurality of interfaces for interfacing to data devices. The processor services the interfaces using an interrupt bus including unidirectional inbound and outbound buses. The inbound bus includes one lead for each interface, with each lead having a fixed priority level assigned by the processor. Each interface has access to all leads of the inbound bus. The processor sends commands over the outbound bus to dynamically control the connection of an interface to a lead of the inbound bus.
    Type: Grant
    Filed: October 26, 1987
    Date of Patent: April 3, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: Craig W. Jensen, Frederick R. Keller
  • Patent number: 4821179
    Abstract: A data processing system includes a processor unit (CPU) connected over a CPU bus to a plurality of memory components, but is not connected to any input-output (I/O) component of the system. The system I/O component(s) connect to the memories over an I/O bus. A method and apparatus is disclosed for selecting one of the memories to be used for communications between the processor unit and the I/O components. Also, a method for determining which I/O components are in the system.
    Type: Grant
    Filed: August 8, 1985
    Date of Patent: April 11, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Information Systems
    Inventors: Craig W. Jensen, Frederick R. Keller, Joel I. Morrow, Eric A. Roth