The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 1999
Filed:
Sep. 11, 1997
Toshiyuki Shimizu, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A data transfer system which improves efficiency in direct data transfer from an input device with a first-in first-out (FIFO) memory serving as a buffer to a memory and from a memory to an output device with a first-in first-out (FIFO) memory serving as a buffer. The data is transferred from the input device to the memory and from the memory to the output device by meeting the requirement of address alignment without restricting data transfer to fixed multiples of, for example, four words. A memory write controller is informed as to how much data is present in the buffer in the input device. The controller checks memory address alignment to determine the transfer size of data from the input device to the memory. A memory read controller is also informed as to how much free space is present in the buffer in the output device and checks the memory address alignment to determine the transfer size of data from the memory to the output device. The request lines from the input device are used to indicate that data in the FIFO is either one word or more, two words or more or four words or more. A maximum data transfer size is determined automatically from an amount of data stored in the buffer of the input device and a check on memory address alignment.