#include <stdio.h>
#include <stdint.h>

int main(void){                 //X
   uint8_t x = 0xC0;      //1100 0000  
   uint8_t mask = 4;      //0000 0100
                          //---------
                          //1100 0100 &
                          //1111 1011
                          //---------
                          //1100 0000
   
   printf("0x%X\n",x);

   //set the bit - make bit equal to 1
   x = x | mask;
    
   printf("0x%X\n",x);
   
  
   //unset the bit - make bit equal to 0        
   x = x & ~mask;       
   
   printf("0x%X\n",x);
   
 
   return 0;
}