MCT8329A: STEP input timing and voltage at power-on

Hi, 

Could you please answer Q1 and Q2 for the DRV8424 and MCT8329A respectively?

Q1
How long should the STEP input be after the power is turned on?

Q2
Related to Q1. Should the STEP input be held low at power up? Is there any problem even if it is fixed to Hi? Or is there no problem even if STEP input is performed when the power is turned on?

Thanks,

Conor