80. Register Bitfields Using Struct Overlay

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

typedef union {
    struct {
        uint8_t enable    : 1;
        uint8_t mode      : 2;
        uint8_t interrupt : 1;
        uint8_t reserved  : 4;
    } bits;
    uint8_t reg;
} ControlRegister;

int main() {
    uint8_t e, m, i;
    scanf("%hhu %hhu %hhu", &e, &m, &i);
    ControlRegister res ;  
    res.bits.enable = e ;
    res.bits.mode = m ; 
    res.bits.interrupt = i ; 
    printf("%d" , res.reg) ; 
    return 0;
}