So I finally got my Xplained 21 yesterday and have been playing with it mostly trying to understand the hardware abstraction
With my AVR microcontrollers I would start off by doing as much as i could by accessing the registers directly , I am attempting to do the same with this board
However youll see in the code below that the things i have commented out do not work in the while 1 loop , not even the function call to that very efficient delay.
my defines are to the correct memory addresses and offsets , funny thing is if i put them outside of the while(1) loop they work as expected... so i know the memory mapping is right.
Again this is just for my personal learning purposes , but i would like to understand why?
And yes I can get a proper delay with the systick handler etc.. but even then nothing seems to work in my while loop
#include "sam.h"
#define myDIR (*(( uint32_t*)(0x41004400)))
#define myOUTSET (*(( uint32_t*)(0x41004418)))
#define myOUTCLR (*(( uint32_t*)(0x41004414)))
#define myTOGGLE (*(( uint32_t*)(0x4100441C)))
#define myPM (*(( uint32_t*)(0x4000041C)))
#define myPMUX (*(( uint32_t*)(0x40000434)))
//prototype
void my_efficient_delay(void);
void my_efficient_delay()
{
for (int x = 0 ; x < 10000 ; x++);
}
int main(void)
{
SystemInit();
PORT->Group[0].DIR.reg = 1<<8;
//myDIR = 1<<8;
while(1)
{
PORT->Group[0].OUTTGL.reg = 1<<8 ;
//myTOGGLE = 1<<8;
// my_efficient_delay();
for (int x = 0 ; x < 10000 ; x++);
}
}
