Inverted Direction Pin

I am trying to use the TB66 motor driver. It requires two direction pins to select the direction of the motor.

I would like to be able to select a second direction pin from the Pi that is inverted form the other pin.

Example
Pin 4 and and 5 are the selected pins to set direction.

Pin 4 HIGH Pin 5 LOW = motor forward 
Pin 4 LOW Pin 5 HIGH = motor reverse (pump down)