Patent ID: 7996692

Claim:
An information processing apparatus equipped with a microprocessor, comprising: an operation clock signal generator that generates a frequency-variable operation clock signal supplied to the microprocessor; and a power supply voltage generator that determines a value of a power supply voltage to be supplied to the microprocessor according to a logarithm of a frequency of the operation clock signal and generates the power supply voltage, wherein the power supply voltage generator determines the value of the power supply voltage to be proportional to the logarithm of the frequency of the operation clock signal according to following equations: K= ( E max− E min)/(log( F max)−log( F min)) (1) When Fclk<Fmin, Evdd=Emin (2) When Fmin≦Fclk≦Fmax, Evdd=K ·(log(Fclk)−log( F min))+ E min (3) When Fmax<Fclk, Evdd=Emax (4) wherein Fclk is the frequency of the operation clock signal, Fmin is a lower frequency value, Fmax is an upper frequency value, Evdd is the value of the power supply voltage, Emin is a lower voltage limit value of the power supply voltage, and Emax is an upper voltage limit value of the power supply voltage.