67. Control Register Using Nested Bitfields

#include <stdio.h>

typedef union {
    unsigned char reg;
    struct {
        unsigned char enable : 1;
        unsigned char mode : 1;
        unsigned char priority : 2;
        unsigned char reserved : 4;
    } bits;
} ControlRegister;

// Write your logic here
int validate_register(ControlRegister *ctrl) {
    // uint8_t mask_reserved = 0xF0U;
    // uint8_t mask_priority = 0x0CU;
    bool ret = false;
    if (ctrl->bits.enable && ctrl->bits.priority!=3 && ctrl->bits.reserved==0) 
        ret = true;
    return ret;
}

int main() {
    ControlRegister ctrl;
    scanf("%hhx", &ctrl.reg);

    int result = validate_register(&ctrl);
    printf("%d", result);

    return 0;
}