DRV8452: PWPR Torque Setting in Hardware Version ?

Tool/software:

Hi,

we are trying to use DRV8452PWPR Version, which is hardware version.v i have tried running motor in 1/128 uStep and 1/256uSteps but no effect in increased torque.

But our motor is taking just 0.2A and when we try to give load to motor shaft it vibrates. I understand stepper motor is not able to handle torque.

I need help in 

1) Disable Auto Torque / Stall.

2) Increase Torque ? 

Please guide for the same.