PWM signal to step/direction signals

Anybody know of a circuit or IC that is capable of taking a PWM signal as
used for RC angular servos and outputs step and direction signals with
output adjustable for scaling? Basically, I would have a PWM signal for an
angular servo and would like to use it to run a stepper through a gear
reducer to increase resolution and torque. I couldn't find much on the web
on this so any information would be greatly appreciated.

Regards,

Howard Bailey