Radio oscillator tuning
View Patent ↗Tuning a radio oscillator frequency to a reference frequency is disclosed. A radio oscillator is set using a predetermined value loaded into an adjustment bit array. A highest selected bit is selected to be used in locating a final tuned value for the adjustment bit array. The final tuned value is determined by successively setting a selected bit starting with the highest selected bit in the adjustment bit array. And, the selected bit value in the final tuned value is determined using a measurement of the radio oscillator frequency and its relation to a reference frequency.
1. A method for tuning a radio oscillator frequency to a reference frequency comprising:
setting a radio oscillator using a predetermined value loaded into an adjustment bit array;
selecting a highest selected bit to be used in locating a final tuned value for the adjustment bit array;
determining the final tuned value by successively setting a selected bit starting with the highest selected bit in the adjustment bit array; and
determining the selected bit value in the final tuned value using a measurement of the radio oscillator frequency and its relation to a reference frequency.
2. A method as in claim 1 , wherein the final tuned value is stored in a digital memory.
3. A method as in claim 1 , wherein the predetermined value loaded into the adjustment bit array comprises a previously stored final tuned value.
4. A method as in claim 1 , wherein the reference frequency is derived from one or more of the following: a crystal oscillator, a watch crystal oscillator, a quartz crystal oscillator, an oscillator, and a 32.768 KHz oscillator.
5. A method as in claim 1 , further comprising disabling tuning circuitry after determining the final tuned value.
6. A method as in claim 1 , further comprising disabling tuning circuitry after determining the final tuned value, wherein the tuning circuitry includes one or more of the following: an oscillator frequency measurement counter, a frequency locking engine, and an oscillator divider.
7. A method as in claim 1 , wherein setting the radio oscillator includes adjusting a capacitor value.
8. A method as in claim 1 , wherein setting the radio oscillator includes adjusting a capacitor value using the adjustment bit array.
9. A method as in claim 8 , wherein adjusting the capacitor value includes setting a switch in a circuit comprising:
a first capacitor including a first capacitor first terminal and a first capacitor second terminal;
a second capacitor including a second capacitor first terminal and a second capacitor second terminal;
a third capacitor including a third capacitor first terminal and a third capacitor second terminal;
wherein the first capacitor second terminal is connected to the second capacitor first terminal;
wherein the first capacitor second terminal is connected to the third capacitor first terminal; and
wherein the third capacitor second terminal is connected to a switch first terminal.
10. A method as in claim 8 , wherein the second capacitor second terminal is connected to one of the following: ground or a low impedance voltage.
11. A method as in claim 1 , wherein the adjustment bit array includes a coarse adjustment set of bits.
12. A method as in claim 1 , wherein the adjustment bit array includes a fine adjustment set of bits.
13. A method as in claim 1 , wherein the adjustment bit array includes a coarse adjustment set of bits and wherein the coarse bits adjust a capacitor in binary weighted values.
14. A method as in claim 1 , wherein the adjustment bit array includes a fine adjustment set of bits and wherein the fine bits adjust a capacitor in non-monotonically weighted values.
15. A method as in claim 1 , wherein the adjustment bit array includes a modulation array used to directly modulate the radio frequency oscillator in response to a stream of data.
16. A method as in claim 1 , wherein the adjustment bit array includes a non-monotonically weighted portion, wherein each more significant bit of the non-monotonically weighted portion of the adjustment bit array adjusts switches that provide a change in capacitance less than the sum of the change of capacitances of all lesser significant bits.
17. A method as in claim 1 , wherein the measurement of the oscillator frequency includes counting oscillations from the oscillator for a number of periods of a reference clock.
18. A method as in claim 1 , wherein the measurement of the oscillator frequency includes dividing down the oscillations from the oscillator.
19. A method as in claim 1 , wherein the predetermined value in the adjustment bit array sets the oscillator to a maximum frequency.
20. A method as in claim 19 , wherein the bits are successively set such that the oscillator oscillates at lower frequencies.
21. A method as in claim 1 , wherein the predetermined value in the adjustment bit array sets the oscillator to a minimum frequency.
22. A method as in claim 21 , wherein the bits are successively set such that the oscillator oscillates at higher frequencies.
23. A method as in claim 1 , wherein the bits are successively set from highest bit to lowest bit.
24. A method as in claim 1 , wherein the final tuned value in the adjustment bit array is stored.
25. A computer program product for tuning a radio oscillator frequency to a reference frequency, the computer program product being embodied in a computer readable medium and comprising computer instructions for:
setting a radio oscillator using a predetermined value loaded into an adjustment bit array;
selecting a highest selected bit to be used in locating a final tuned value for the adjustment bit array;
determining the final tuned value by successively setting a selected bit starting with the highest selected bit in the adjustment bit array; and
determining the selected bit value in the final tuned value using a measurement of the radio oscillator frequency and its relation to a reference frequency.
26. A system for tuning a radio oscillator frequency to a reference frequency comprising:
a processor; and
a memory coupled with the processor, wherein the memory is configured to provide the processor with instructions which when executed cause the processor to:
set a radio oscillator using a predetermined value loaded into an adjustment bit array;
select a highest selected bit to be used in locating a final tuned value for the adjustment bit array;
determine the final tuned value by successively setting a selected bit starting with the highest selected bit in the adjustment bit array; and
determine the selected bit value in the final tuned value using a measurement of the radio oscillator frequency and its relation to a reference frequency.