Self power audit and control circuitry for microprocessor functional units

The present invention relates to an apparatus and method for reducing power dissipation in microprocessors and, in particular, to self power audit and control circuitry for microprocessor functional units. A method and apparatus for reducing power dissipation within a functional unit of a microprocessor includes a power sensing circuit for sensing power dissipation of the functional unit. A low power mode identifying circuit identifies when the measured power dissipation of the functional unit exceeds a predetermined amount or value. Upon such a condition, a low power mode circuit operates the functional unit in a low power mode thereby reducing its power dissipation. Operation of the functional unit in the low power mode continues until the power dissipation reaches a safe level. The functional unit internally determines power dissipation and selectively enters a low power mode to reduce power dissipation of the functional unit. Low power mode operation of the functional unit reduces power dissipation of the functional unit.