Patent ID: 7302599

Claim:
A power management controller for instantaneous frequency-based microprocessor power management, comprising: a first PLL that generates a first core source clock signal at a first frequency based on a bus clock signal; a second PLL that generates a second core source clock signal at a programmable frequency based on a frequency control signal and said bus clock signals, wherein said second PLL generates a lock signal when said second core source clock signal is at a frequency indicated by said frequency control signal; select logic that selects between said first and second core source clock signals to provide a core clock signal for the microprocessor based on a select signal; and source control logic that detects power conditions via at least one power sense signal, that provides said frequency control signal according to said power conditions, and that provides said select signal, wherein said source control logic controls said select signal to switch from said first core source clock signal to said second core source clock signal in response to said lock signal.