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.

Date of Patent:
Aug. 15, 2000

Filed:

May. 12, 1998
Applicant:
Inventors:

Takayasu Hirai, Osaka, JP;

Kazuhiko Hara, Hyogo, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
710 28 ; 710 28 ; 710 23 ; 710 18 ; 711154 ;
Abstract

A processor used in a synchronous data transfer system in which a processor, a direct memory access controller and peripheral devices are connected to a memory via the same bus, includes a detection circuit for detecting whether the processor uses the bus in a forthcoming cycle, and a control circuit having a first terminal for acknowledging a request signal from the direct memory access controller requesting a use of the bus, only when the detection circuit detects that the processor does not use the bus in the forthcoming cycle, wherein the control circuit discards a right to use the bus and outputs a response signal to the direct memory access controller indicating that the processor grants the right to use the bus to the direct memory access controller, when the request signal is acknowledged.


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