From an old rc car.
I have replaced pins from an IC with digital sources.
The block on the left seems to be an astable oscillator to provide pwm to the motor.
There are two digital sources that control the oscillator. The four combinations provide no power, half dc power or pwm at a fixed cycle.
The block on the right is an H bridge. There's no protection in the schematic but the motor had a coil on each terminal and a capacitor across.
