SOFTWARE DEBOUNCING AND NOISE FILTERING MODULES FOR INTERRUPTS

摘要

Systems and methods for debouncing a signal line within a computer device are provided. The mechanical nature of physical buttons and switches oftentimes present irregular or noisy signals on a signal line when depressed by a user. Thus, noise and/or irregular waveforms may be present on a signal line that is monitored to produce interrupt signals, when deemed valid and genuine. In many embodiments given herein, debounce modules and techniques set a debounce interval timer and/or a noise filtering interval timer in which debounce modules and/or techniques may note whether the signal line is still asserted (e.g., possibly a genuine interrupt signal) during the debounce interval timer and stable (e.g., no further interrupts have fired) during the noise filtering interval timer.

主权项

1. A method for debouncing a signal line, the method comprising:
detecting an assertion of a signal on said signal line; masking said signal line; setting a first timer; upon the expiration of said first timer, unmasking said signal line; setting a second timer; upon the expiration of said second timer, noting if said signal line is still asserted; if said signal line is still asserted, invoking an interrupt signal.