who can give me the example program about PLL to drive the motor

I want to drive the motor using Shield 298A by means of PLL ,not PWM . who can give me an example or a link? thank you! my board is arduino mega 2560

PLL means Phased Locked Loop to me. Is that what you mean ?

If so, where are you going to get the reference signal ? Do you perhaps mean that you want to use feedback from the rotation of the wheels to control their speed ?

Please explain more what you want to do.

PLL means Phased Locked Loop to me.

It means Program Ladder Logic to me.

A clarification of what PLL means to OP is going to be essential.

Waiting with bated breath .......

Waiting with bated breath .......

Man, you should try some mouthwash. Smells more like garlic breath. :P