Spread spectrum clock and reference signal generator

An apparatus, comprising:

• a reference resonator to provide a reference signal having a resonant frequency;
• a coefficient register to store a plurality of coefficients;
• a plurality of controlled reactance modules coupled to the reference resonator and to the coefficient register;
• and
• a spread spectrum controller coupled to the coefficient register, the spread spectrum controller comprising a counter and a state machine, the counter to provide a plurality of time interval counts;
• and the state machine, in response to a predetermined time interval count of the plurality of time interval counts, to select or modify a plurality of coefficients from the coefficient register to provide the reference signal at a plurality of different resonant frequencies during a selected or predetermined time period.

A spread spectrum clock generator comprising:

• a reference oscillator to provide a reference signal having a reference frequency;
• a coefficient register to store a plurality of coefficients;
• a plurality of controlled reactance modules coupled to the reference oscillator and to the coefficient register, each controlled reactance module responsive to a corresponding coefficient of the plurality of coefficients to modify an amount of effective reactance coupled to the reference oscillator;
• and
• a spread spectrum controller comprising a counter, an adder and a state machine, the counter to provide a plurality of time interval counts and the state machine, in response to a predetermined time interval count of the plurality of time interval counts, to select or modify a plurality of coefficients from the coefficient register to control the reference oscillator to generate a reference signal at a plurality of different reference frequencies.

A method of spread-spectrum clock generation, comprising:

• generating a reference signal from a reference oscillator;
• counting the reference signal to provide a plurality of time interval counts;
• and
• modifying a plurality of coefficients to modify an amount of reactance effectively coupled to the reference oscillator at a plurality of predetermined time interval counts of the plurality of time interval counts to generate a spread-spectrum reference signal at a plurality of different reference frequencies during a predetermined time period.