i have seen throughout the search engine, PWM should generated for DC motors. but i haven`t seen some one used PWM with stepper motors.

so my qyestion is that how to drive stepper motrs without PWM, if its possible according to the interface line??

It's in the name, you do not drive stepper motors with PWM, you drive them with steps

On each pulse the stepper motor will move an amount e.g. 3 degrees determined by the motor design.

What you have to do is to accelerate and decellerate the steps since hitting a stepper motor standing still with full speed steps will have no effect.

Erik