Methods of clock throttling in an integrated circuit

Abstract

Thermal throttling control to safely throttle clocks OFF and ON in an integrated circuit. Digital thermal throttling control is provided to gradually throttle a clock's frequency from ON to OFF and from OFF to ON. The gradual throttling can minimize an instantaneous current rise that would otherwise occur with a rapid shut OFF and a rapid turn ON of a clock. Included are methods and apparatus for digital thermal throttle control in an integrated circuit.

1 . A method comprising:
 periodically determining a total level of switching activity in an integrated circuit to form a measure of global functional activity;   comparing the measure of global functional activity with a predetermined limit of activity;   if the measure of global functional activity meets or exceeds the predetermined limit of activity then
 gradually reducing a first frequency of clocking of circuitry in the integrated circuit to zero to stop the clocking of circuitry in the integrated circuit, 
 waiting a first predetermined time after stopping the clocking of circuitry in the integrated circuit, and 
 starting the clocking of circuitry in the integrated circuit at a second frequency less than the first frequency; 
   and,   if the measure of global functional activity does not meet or exceed the predetermined limit of activity, then repeating the periodically determining and the comparing.