Calibration for spread spectrum clock generator and method therefor

In one form, a spread spectrum clock generator includes a clock generator and a modulator. The clock generator modulates a frequency of a reference clock signal using a modulation signal to provide a spread spectrum clock signal. The clock generator has a characteristic transfer function that varies with values of a parameter. The modulator generates the modulation signal according to a desired profile conditioned by an inverse of the characteristic transfer function of the clock generator at a current value of the parameter.