Proteus, Arduino control of a stepper motor with L297 and L298

Hi,

First of all sorry for my bad english but I need help to finish my school work.

I have to propose a cabling and a flow chart in Proteus to run a stepper motor with an angle which measure 20° in 10 secondes.
Nominal Volt : 3.8 / Step Angle : 0.25 / Max RPM : 360 / Coil Resi : 5.6 / Coil Induc : 4mH

I tried to do since 4h but I don't understand, can someone explains me how does this work ?
Here is my diagram...