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:
Apr. 21, 2009
Filed:
Sep. 29, 2005
Applicant:
Tetsuo Hatakeyama, Tachikawa, JP;
Inventor:
Tetsuo Hatakeyama, Tachikawa, JP;
Assignee:
Kabushiki Kaisha Toshiba, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F 13/28 (2006.01);
U.S. Cl.
CPC ...
Abstract
An I/O controller to which an I/O device is connected includes a DMA controller (DMAC) and an access control unit (ACU). The DMAC executes DMA transfer in accordance with data transfer control information set in a control/status register by a user process. The ACU limits execution of DMA transfer by the DMAC based on access control information set in a control/status register by a privileged process, and disables the DMAC from accessing any memory area other than the memory area that can be accessed by the user process.