What is the fastest way to read/write GPIOs on SAMD21 boards?

[John41234]

I find using the structure pointer method quite awkward to use as im more used to the tradition notation

Is the pointer method faster than direct register access? or about the same?

forexample the code you made

@westfw

Heh. This will do 20ns pulses...

static inline void fastWrite(int bitnum, int val) {
  if (val)
    PORT_IOBUS->Group[0].OUTSET.reg = (1 << bitnum);
  else
    PORT_IOBUS->Group[0].OUTCLR.reg = (1 << bitnum);
  asm volatile ("" ::: "memory");
}

vs

@John41234

``
REG_PORT_DIRSET1 = PORT_PB27; // set PB27 to output
REG_PORT_OUTSET1 = PORT_PB27; // set PB27 HIGH
REG_PORT_OUTCLR1 = PORT_PB27; // set PB00 LOW