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. 15, 1997
Filed:
Jul. 21, 1993
Michael E Spak, Kyle, TX (US);
Dale E Gulick, Austin, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A keypad scanner for a keypad having a plurality of keys which may be pressed into a down state includes circuitry for detecting when no or any key is pressed down and thereupon generating a no or any key down signal, circuitry for detecting when more than one key is pressed down and thereupon generating a multiple key down signal, and an interrupt generator coupled to the aforementioned circuitry. The interrupt generator itself includes circuitry for detecting a change in no or any key down signal level, circuitry for detecting a change in multiple key down signal level, and circuitry for generating an interrupt signal when either the circuitry for detecting a change in no or any key down signal level or the circuitry for detecting a change in multiple key down signal level detects a change.