Abstract: Disclosed is directed to a speed-level calculator and calculating method for dynamic voltage scaling. The speed-level calculator comprises a deadline counter, a shifter, and a fixed-point multiplier. The deadline counter calculates the residual time D from current time to each task deadline for completing an episode. The shifter generates a D? value by shifting the D value to the right for e-m bits, and takes the decimal fraction part of the D? value for m bits. The speed-level calculator further comprises a saturation control circuit to detect if an overflow occurs on the D? value. According to a pre-calculated parameter ?i corresponding to each task Ti, the fixed-point multiplier performs the multiplication of D? and ?i. After completing saturation and rounding on the multiplication result, a corresponding clock period is generated by taking the integer part. This clock period is used as speed-level to switch the processor voltage and frequency.

Abstract: Disclosed is directed to a speed-level calculator and calculating method for dynamic voltage scaling. The speed-level calculator comprises a deadline counter, a shifter, and a fixed-point multiplier. The deadline counter calculates the residual time D from current time through to each task deadline for completing an episode. The shifter generates a D? value by shifting the D value to the right for e?m bits, and takes the decimal fraction part of the D? value for m bits. The speed-level calculator further comprises a saturation control circuit to detect if an overflow occurs on the D? value. According to a pre-calculated parameter ai corresponding to each task Ti, the fixed-point multiplier performs the multiplication of D? and ?i. After completing saturation and rounding on the multiplication result, a corresponding clock period is generated by taking the integer part. This clock period is used as speed-level to switch the processor voltage and frequency.