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. 02, 1984
Filed:
Nov. 19, 1981
Shiro Oishi, Hadano, JP;
Masatsugu Shinozaki, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A data proessing system includes a processor, a memory, a direct memory accessing (DMA) control unit and an input/output adapter. A memory area of a given capacity is reserved in the memory for storing control information transferred between the processor and the adapter. For transfer of the control information, the adapter accesses the control information stored in the memory area through direct memory accessing under control of the DMA control unit while the processor can make access to the control information through a memory read/write command. By storing at the predetermined area of the memory the control information transferred between the processor and the adapter, the quantity of hardware and the number of IC's required for implementing the adapter can be significantly reduced. Conflicting access requests to the main memory area by the processor and adapter are prevented through time-division control of the memory bus.