Data Watch DWT on RPI3 without debuigger

hi,

I am trying to use the Data Watch and Trace  natively on RPI3 without debugger to count Cycle but got a core dump. here the code to compile and run on a RPI3. . My objective is to count cycle to do accurate benchmarking.

I have a core dumped on line *DEMCR = *DEMCR | 0x01000000; 

What is the issue here ?

Thanks for any help. Regards

 #include <stdint.h>

#include <stdio.h>

#include <stdlib.h> volatile uint32_t count = 0;  

// addresses of registers

volatile uint32_t *DWT_CONTROL = (uint32_t *)0xE0001000;

volatile uint32_t *DWT_CYCCNT = (uint32_t *)0xE0001004;

volatile uint32_t *DEMCR = (uint32_t *)0xE000EDFC;

int main () { // enable the use DWT

printf("Init \n");

*DEMCR = *DEMCR | 0x01000000;

printf(" never here ? \n");  

// Reset cycle counter *DWT_CYCCNT = 0; // enable cycle counter

*DWT_CONTROL = *DWT_CONTROL | 1 ;  

// some code here

// number of cycles stored in count variable

count = *DWT_CYCCNT;

printf("count = %d \n",count);

return 0; }  

The output is : Init Segmentation fault (core dumped)