2. Extract the Nibble from an 8-bit Register

#include <stdio.h>
unsigned char extractNibble(unsigned char reg, int pos) {
   if (pos == 0) {
       return reg & 0x0F;  // Extract lower nibble
   } else {
       return (reg >> 4) & 0x0F;  // Extract upper nibble
   }
}
int main() {
   unsigned char reg;
   int pos;
   scanf("%hhu %d", &reg, &pos);
   printf("%d", extractNibble(reg, pos));
   return 0;
}

Explanation:

• reg & 0x0F; → Extracts lower nibble (last 4 bits).
• (reg >> 4) & 0x0F; → Extracts upper nibble (shift right by 4 bits).