Simplified phase lock loop control model system and method
A phase-locked loop control system and method are described. Present invention phase-locked loop control systems and methods facilitate control of phase-lock loop operations. In one embodiment, phase-lock loop control systems and methods are utilized in the implementation of a modulated frequency synthesizer for facilitating efficient frequency spreading over a designated spectrum. It is appreciated that present invention embodiments can have a variety of implementations and can be compatible with vector accumulation. For example, a phase-locked loop control system or method can facilitate generation of a variety of modulation patterns, including but not necessarily limited to linear or non-linear modulation, standard or non-standard modulation, etc.
1. A frequency synthesizer comprising:
a phase lock loop component configured to create a spread spectrum frequency output signal;
a phase lock loop controller interface configured to control the phase lock loop component, wherein feedback divider control values are adjusted; and
a control pattern generation component configured to generate said feedback divider control values, wherein a modulation control value contribution of each of said feedback divider control values is proportional to the difference from each of said feedback divider control values to an average of said feedback divider control values, wherein said proportion is equal to a new feedback divider control value minus an average feedback divider control value divided by said average feedback divider control value, wherein said control pattern generation component includes:
an input modulation signal mixer configured to produce an error modulated signal;
a future error generation component configured to produce a concurrent plurality of error signals based upon said error modulated signal and a future vector;
an error selection component configured to select one of said concurrent plurality of error signals and an identification of a selected error signal; and
a control value selection component configured to select a feedback loop control value based upon said selected one of said concurrent plurality of error signals.
2. A frequency synthesizer of claim 1 wherein each feedback divider control value is associated with a contribution to the VCO phase error.
3. A frequency synthesizer of claim 1 wherein in each modulation step P is selected so that its contribution changes the VCO phase error to the desired value.
4. A frequency spreading control pattern generation system of claim 1 wherein the input modulation signal mixer mixes an input modulation signal with said selected error signals.
5. A frequency spreading control pattern generation system of claim 1 said control value corresponds to a modulo or count value of a feedback loop divider.
6. A feedback loop divider control value adjustment method comprising:
receiving an initial average target frequency;
receiving a concurrent plurality of error values;
summing the most significant bits of said concurrent plurality of error values;
selecting one of said concurrent plurality of error values based upon results of said summing; and
forwarding said results of said summing as an identification of said selected one of said concurrent plurality of error values; and
adjusting said initial average target frequency in accordance with a feedback divider control value proportion, wherein said feedback divider control value is associated with a contribution to the VCO phase error.
7. A feedback loop divider control value adjustment method of claim 6 wherein said proportion is defined by difference from each of said feedback divider control values to an average of said feedback divider control values.
8. A feedback loop divider control value adjustment method of claim 6 wherein said proportion is associated with an integer vector contribution and scaled phase error.
9. A feedback loop divider control value adjustment method of claim 6 further comprising selecting a best feedback divider control value so that a VCO phase error is altered towards a target value.
10. A feedback loop divider control value adjustment method of claim 6 wherein said method is directed by software instructions.
11. A feedback loop divider control value adjustment method of claim 6 wherein an offset modulates said initial feedback loop divider control value and the result is added to a base feedback loop divider control value.
12. A computer readable medium for storing instructions for directing a processor to implement a feedback loop divider control value adjustment method comprising:
receiving an initial average target frequency;
receiving a concurrent plurality of error values;
summing the most significant bits of said concurrent plurality of error values;
selecting, using an error selection component, one of said concurrent plurality of error values based upon results of said summing;
forwarding said results of said summing as an identification of said selected one of said concurrent plurality of error values; and
adjusting said initial average target frequency in accordance with a feedback divider control value proportion, wherein said feedback divider control value is associated with a contribution to a VCO phase error.
13. A computer readable medium of claim 12 wherein said proportion is defined by difference from each of said feedback divider control values to an average of said feedback divider control values.
14. A computer readable medium of claim 12 wherein said proportion is associated with an integer vector contribution and scaled phase error.
15. A computer readable medium of claim 12 further comprising performing a delta sigma selection process.