title: How to enable ART accelerator STM32F407VGT6
body: <p>I keep reading about the ART accelerator on the STM32F407VGT6 and zero wait states at 168MHz and it is mentioned briefly in the data sheet but I can't find anywhere how to enable it.
  There is a prefetch option in the FLASH_ACR register but enabling it causes my board to stop 
  working. Not sure if this is the same thing. Is ART even something that needs to be enabled or is it enabled by default? I notice in the errata for this chip that the ART was not working in A version but has been "fixed" in the current Z rev.</p>
  
  <p>Thanks</p>