Frequency Modulation in Real Time

Using Arduino Project Guidance
1

I need reduce the frequency of a roughly 20khz - 100khz +5 volt rectified, square wave signal by 20% and output the corrected signal in real time.

Could this be accomplished with an Arduino unit or another microcontroller? Any advice would be greatly appreciated.

Thanks!

2

An Arduino DUE can easily parse an input PWM signal with an input capture up to several MHz. Once the frequency has been detected, do the math to output an equal PWM signal of a 20% reduced frequency.

What is the maximum expected delay between input PWM frequency parsing and the corresponding PWM output ?