STM32F103C8 writing driver and can't change register bit value

Question

this is my code, when I try to change ADC1 register bit I change address of ADC and offset and it works well. but when I wan to change ADC CR2 value it doesn't work. when I run this code, ADC2 is enabled but CONT value is 0.

I tried to enable all ADC2 register values to 1 using for loop but no one change values all are 0.

Code :

#include <stdint.h>

#define RCC_BASE_ADDR       0x40021000UL
#define RCC_APB2_ENR_OFFSET 0x18UL
#define RCC_APB2_ENR_ADDR   (RCC_BASE_ADDR + RCC_APB2_ENR_OFFSET)

#define ADC_BASE_ADDR       0x40012800UL
#define ADC_CR2_ENR_OFFSET  0x08UL
#define ADC_CR2_ENR_ADDR    (ADC_BASE_ADDR + ADC_CR2_ENR_OFFSET)

int main()
{
  //write address values in variable
  uint32_t *pRccApb2Enr = (uint32_t *)RCC_APB2_ENR_ADDR;
  uint32_t *pAdcCr2Reg  = (uint32_t *)ADC_CR2_ENR_ADDR;
  
  //enable peripheral clock for ADC1
  *pRccApb2Enr |= (1<<10);
  //enable CONT bit
  *pAdcCr2Reg |= (1<<1);
  
  while(1);
  
  return 0;
}

Answer 1

I suspect that the lack of volatile and the fact that code is optimised (suggested by the "locals" showing as "unavailable"), is probably the cause of your problem.

Defining your own register definitions is unnecessary, ill-advised, and error prone. The vendor supplied header (stm32f1xx.h) is far safer.

In this case you have pointers that are written to but never read, and not declared volatile, so the compiler does nothing (as an optimisation). The compiler does not know that the pointers refer to registers, rather than simply regular memory.