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:
Aug. 13, 1996
Filed:
Apr. 17, 1995
Larry D Hewitt, Austin, TX (US);
Ryan Feemster, Austin, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A cascade of triggering circuits sequentially activates a series of parallel pull-down paths in reflexive response to a pull-down signal indicating correspondence between the potential on a capacitively loaded port and a selectable threshold voltage. The triggering circuits are clocked with a common signal to sequentially propagate the pull-down signal from prior to subsequent triggering stages to sequentially activate corresponding parallel paths. In a preferred embodiment, the D flip-flops of a sequential cascade control multiple pull-down paths to regulate charging and discharging of a joystick capacitive load on a monolithic audio personal computer IC game port. To initiate charging of the joystick capacitor, the flip-flops simultaneously disable the pull-down paths in response to a system WRITE signal. To discharge the joystick capacitor, the flip-flops sequentially propagate a comparator derived pull-down signal to sequentially enable the pull-down paths to controllably dissipate the accumulated charge.