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. 02, 1991
Filed:
Mar. 20, 1989
Kunihiko Nakada, Kodaira, JP;
Yasushi Akao, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A data processor controller for a microprogramming system is constructed with a single operation execution unit serving both a microprocessor and a peripheral device such as a direct memory access controller. In addition to the single operation execution unit, the controller includes a micro-memory which stores micro-instructions for controlling both the microprocessor and the peripheral device, and address registers, multiplexers and decoders integrated into a single device. Different ROM address registers in the controller are separately assigned to provide an address decoder with addresses of selected memory locations in the micro-memory containing the micro-instructions for the microprocessor and the peripheral device, thereby enabling the controller, through multiplexing between the address registers, to use the arithmetic execution unit, counter and bus interface of the single operation exeuction unit on a time sharing basis, for controlling the functions of both the microprocessor and the peripheral device.