Using direct registers with Due

[SupArdu]

Hi,
is there a difference between
PIOC->PIO_PER = something
and
REG_PIOC_PER = something

[MartinL]

Hi @SupArdu

Both are acceptable and reference the same register, however the form:

PIOC->PIO_PER = ...

...is usually preferred.

One reason is that it's slightly more flexible when accessing an array of registers, for example when iterating through a number of PWM channels:

for (uint8_t i = 0; i < PWMCH_NUM_NUMBER; i++)    // Loop for each PWM channel (8 in total)
{
  PWM->PWM_CH_NUM[i].PWM_CMR = PWM_CMR_CALG | PWM_CMR_CPRE_CLKA;     // Enable dual slope PWM and set the clock source as CLKA
  PWM->PWM_CH_NUM[i].PWM_CPRD = 2040;                                // Set the PWM frequency 2MHz/(2 * 2040) = 490Hz;
}