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:
Oct. 19, 1999
Filed:
Jun. 05, 1997
Applicant:
Inventors:
Hiromi Maeda, Tokyo, JP;
Masayuki Hata, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
710 28 ; 710108 ; 710 22 ; 710 25 ;
Abstract
A data processing unit capable of solving a conventional problem in that a CPU cannot acquire the right of using a bus as long as a DMAC (Direct Memory Access Controller) has that right, and hence the operating ratio of the CPU reduces. A CPU bus is kept disconnected from the DMAC bus as long as the CPU disables the access request to a memory connected to the DMAC bus, and is connected to a DMAC bus in response to the access request unless the DMAC has the right of using a DMAC bus.