Validate Configuration Register Layout

Code

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

typedef struct {
    unsigned short reg;
} ConfigRegister;

typedef union {
    unsigned short value;
    struct {
        uint8_t enable : 1;
        uint8_t mode : 1;
        uint8_t priority : 2;
        uint16_t reserved : 12; 
    } bits;
} TRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    TRegister reg; 
    reg.value = cfg->reg;
    
    if(reg.bits.enable == 0) {
        return 0;
    }

    if(reg.bits.mode == 3) {
        return 0;
    }

    if(reg.bits.reserved != 0){
        return 0;
    }

    return 1;
}

int main() {
    ConfigRegister cfg;
    scanf("%hx", &cfg.reg);

    int result = validate_config(&cfg);
    printf("%d", result);

    return 0;
}

Solving Approach