DRV8818: Vcc logic supply voltage level

Part Number: DRV8818

Hi,

I am trying to swap this in as a replacement for an older stepper driver, but we were using a 6V supply for that one, the max limit says 5.5V, and I am mesuring around 5.6V-5.7V at the board.  Does anyone know if this will cause an issue where some of our commands would not work?  The jog up a small amount command is only working about 10% of the time.  

Thanks,

Cory