H-bridge topology question
A full H bridge using Nch FETs is often done with discrete FETs or dual half-bridges.  

Normally with positive supplies, and Nch Enhancement FETS preferred, the low side FET gate voltage uses the single supply voltage with PWM.  WHile the High side controls direction with a diode-cap charge pump (from PWM pulsed voltage) to create a boost voltage above Vdd for the high side Vgs. 

The 1st method is only used for special low power motors that can handle the ripple current and power dissipation.

The 2nd method uses dynamic PWM braking to shunt the EMF current to slow down to stop then applies direction change to accelerate in reverse. 

Deadtime in micro-seconds depends on the motor L/R time constants.  

You can start learning with a half-bridge IC Theory of Operation in many places. e.g. here