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:
Jul. 31, 1990
Filed:
Mar. 25, 1988
Applicant:
Inventors:
Ken Sakamura, Tokyo, JP;
Souichi Kobayashi, Itami, JP;
Assignee:
Mitsubihsi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
364200 ; 3642463 ; 364247 ; 3642472 ; 364259 ; 3642591 ; 3642597 ;
Abstract
A device for detecting whether addresses used for accessing in a memory mapped I/O system are present in the I/O area or not is provided. The device includes a mask register for logically ANDing with an incoming address. The output of the ANDing process is exclusive-ORed with an I/O address register. When an operand fetch is made to an I/O area the fetch is suspended during execution of preceding instructions. When the instruction fetch unit seeks an I/O area address, or the address calculation unit seeks an I/O area address, or data is fetched across a boundary of the I/O area, an exception is activated.