Patents by Inventor Shiro Kawata

Shiro Kawata 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).

  • Apparatus and method of performing product-sum operation
    Patent number: 6895423
    Abstract: To perform a product-sum operation by adding third data to a product of first data and second data, a floating point multiplier first multiplies the first data by the second data, and a bit string representing a fixed-point part in the multiplication result is divided into a portion representing more significant digits in the fixed-point part and a portion representing less significant digits in the fixed-point part. Then, a floating point adder first adds less significant multiplication result data having a bit string representing the less significant digits as a fixed-point part to the third data, and then adds the addition result to more significant multiplication result data having a bit string representing the more significant digits as a fixed-point part. A rounding process is performed on the two addition results to obtain a result of the product-sum operation.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: May 17, 2005
    Assignee: Fujitsu Limited
    Inventor: Shiro Kawata
  • Apparatus and method of performing product-sum operation
    Publication number: 20030126174
    Abstract: To perform a product-sum operation by adding third data to a product of first data and second data, a floating point multiplier first multiplies the first data by the second data, and a bit string representing a fixed-point part in the multiplication result is divided into a portion representing more significant digits in the fixed-point part and a portion representing less significant digits in the fixed-point part. Then, a floating point adder first adds less significant multiplication result data having a bit string representing the less significant digits as a fixed-point part to the third data, and then adds the addition result to more significant multiplication result data having a bit string representing the more significant digits as a fixed-point part. A rounding process is performed on the two addition results to obtain a result of the product-sum operation.
    Type: Application
    Filed: March 29, 2002
    Publication date: July 3, 2003
    Applicant: Fujitsu Limited
    Inventor: Shiro Kawata