| 摘要 |
A system and method for programming a digitally tunable oscillator is provided. A desired output frequency is received. A tuning effect of a set of digital tuning words on a crystal resonant frequency is determined, and valid parameters of an algorithm for translating and tuning the crystal resonant frequency to a value within an error tolerance of the desired frequency, based on the determined tuning effect are calculated. Valid parameters are preferably calculated based on an intermediate tuning value, sorted by ascending divide parameter of the algorithm, and then evaluated in sorted order for ability of a tuning effect to null frequency error to within the error tolerance. The valid set of calculated parameters are then programmed into a nonvolatile memory. The oscillator control parameters may remain unprogrammed until all necessary parameters are defined. Because the device may be programmed in a single step, without intermediate presumption of nominal crystal frequency, the final plate process may be unnecessary. A high accuracy may be obtained by searching through the complete set of available parameters for a set that meets a frequency and tolerance specification. The oscillator is preferably a Cypress CY2037 device.
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