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US 7,791,418 B2Granted
Systems and methods for compensating for variations of the output of a real-time clock
AssigneePentad Design Corporation
InventorRichard A. Gros
Life of this patent
Estimating the term…
Abstract
Method and systems are provided for adjusting real-time clocks to compensate for frequency offset, temperature effects, and/or aging effects.
Claims15
A method for correcting offset of a real-time clock, comprising:
- determining a frequency of an output of an oscillator, the frequency being represented as an integer (i) portion and a non-integer (ni) portion;
- and
- counting a first number (a) of “i” oscillations and counting a second number (b) of “i+x” oscillations by dithering between “i” and “i+x” oscillations;
- wherein an average of the first number (a) of “i” oscillations and the second number (b) of “i+x” oscillations is an effective number of oscillations that is approximately the same as the determined frequency.
1 more element
A method for correcting offset of an oscillator of a real-time clock, comprising:
- determining a frequency of an output of an oscillator, the frequency being represented as an integer (i) portion and a non-integer (ni) portion;
- and
- counting a first number (a) of “i” oscillations and counting a second number (b) of “i+1” oscillations by dithering between “i” oscillations and “i+1” oscillations;
- wherein an average of the first number (a) of “i” oscillations and the second number (b) of “i+x” oscillations is an effective number of oscillations that is the same as or approximately the same as the determined frequency.
1 more element
A method for correcting offset of an oscillator of a real-time clock, comprising:
- determining a frequency of an output of an oscillator, the frequency being represented as an integer (i) portion and a non-integer (ni) portion;
- and
- counting a first number (a) of “i” oscillations and counting a second number (b) of “i+1” oscillations by dithering between “i” oscillations and “i+x” oscillations;
- wherein a ratio of (first number (a)*i)+(second number (b)*(i+x)/(first number (a)+second number (b)) is an effective number of oscillations that is the same as or approximately the same as the determined frequency.
1 more element
A real-time clock, comprising:
- a frequency source,
- a counter coupled to the frequency source and being configured to generate a count value based on an output of the frequency source;
- and
- a controller coupled to the counter and being configured to adjust the counter to reflect the actual output of the frequency source by reading the count value from the counter based on the actual output of the frequency source to determine an actual frequency of the output of the frequency source, the frequency being represented as an integer (i) portion and a non-integer (ni) portion, counting a first number (a) of “i” oscillations and counting a second number (b) of “i+1” oscillations by dithering between “i” oscillations and “i+1” oscillations, wherein a ratio of (a*i)+(b*(i+1)/(a+b) is the same as or approximately the same as the determined frequency.
1 more element
Dependencies are inferred from the claim text.