DRV8825: DRV8825 Fstep and mode and others function

Hi Team,

1. In the Fstep of the timing requirement, I want to confirm whether it is a PWM clock, so the requirement for DRV8825 is below 250Khz?
2. As shown in the diagram, is the step size controlled by mode 0~3?
Signals and controls for this part of Decay Mode & DIR?
3. It may be troublesome to provide EVM circuit/BOM (especially if there is a Prefer motor coil)