title: Why I cannot modify some registers of BBB using /dev/mem?
body: <p>I know from TRM that to modify values in control registers I need privileged mode and this can be done with kernel module in Linux.</p>
  
  <p>However, though there is no special mention in TRM, enabling clock for ADC and configuring timebase clock for EPWM is always failed if I try to do these using /dev/mem.</p>
  
  <p>Why I cannot do these using /dev/mem in user space?</p>