Patent ID: 6919703

Claim:
A system, comprising: a PWM (Pulse Width Modulated) signal generator configured to generate a PWM signal; and a tachometer reading unit coupled to the PWM generator and configured to obtain a tachometer reading from a tachometer signal generated by a device powered by the PWM signal, wherein the tachometer reading unit includes a register configured to store a value indicative of a maximum stretching duration; wherein the tachometer reading unit is configured to control the PWM signal generator to stretch a pulse in the PWM signal, wherein the tachometer reading unit is configured to not stretch the pulse longer than the maximum stretching duration indicated by the register; wherein the tachometer reading unit is configured to obtain the tachometer reading during the stretched pulse in the PWM signal; wherein the tachometer reading unit is configured to update the register in response to receiving a new value of the maximum stretching duration.