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:
May. 02, 1978
Filed:
Sep. 17, 1975
Thomas H Bennett, Scottsdale, AZ (US);
Earl F Carlow, Scottsdale, AZ (US);
Edward C Hepworth, Apache Junction, AZ (US);
Wilbur L Mathys, Norristown, PA (US);
William D Mensch, Jr, Norristown, PA (US);
Rodney H Orgill, Norristown, PA (US);
Charles I Peddle, Norristown, PA (US);
Michael F Wiles, Phoenix, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital system includes a microprocessor coupled to a data bus and an address bus. A memory for storing data and instructions is connected to the data bus and the address bus. A peripheral device is connected to an interface adaptor. The interface adaptor is connected to the data bus and the address bus, and performs the function of interfacing between the digital system and a peripheral device, such as a printer or a display device. The microprocessor includes logic circuitry for generating a Valid Memory Address (VMA) output. The VMA output is used to generate an enable signal applied to the memory and the adaptor to enable the memory and the adaptor to be accessed by the microprocessor when the binary address on the address bus is valid and to prevent the memory and the adaptor from being accessed by the microprocessor when the binary address on the address bus is not valid with respect to the microprocessor.