Software debouncing and noise filtering modules for interrupts
First Claim
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 to ignore any additional signals on 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.
2 Assignments
0 Petitions
Accused Products
Abstract
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.
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Citations
18 Claims
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1. A method for debouncing a signal line, the method comprising:
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detecting an assertion of a signal on said signal line; masking said signal line to ignore any additional signals on 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system for debouncing a signal line, said system comprising:
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a controller; a debounce module, said debounce module in communication with a signal; and wherein further said debounce module configured to; detect an assertion of a signal on said signal line; mask said signal line to ignore any additional signals on said signal line; set a first timer; upon the expiration of said first timer, unmask said signal line; set a second timer; upon the expiration of said second timer, note if said signal line is still asserted; if said signal line is still asserted, invoke an interrupt signal. - View Dependent Claims (15, 16, 17, 18)
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Specification