Validate Configuration Register Layout

Code

#include <stdio.h>

typedef struct {
    union {
    unsigned short reg;
    struct {
        unsigned enable   : 1;
        unsigned mode     : 1;
        unsigned priority : 2;
        unsigned reserved : 12;
        } bits;
    };
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    if (cfg->bits.enable != 1)
        return 0;
    if (cfg->bits.priority == 3)
        return 0;
    if (cfg->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