77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    union {
        ConfigRegister cfgr;
        struct {
            unsigned short enable : 1;
            unsigned short mode : 1;
            unsigned short priority : 2;
            unsigned short reserved : 12;
        } bits;
    } struct_val;
    struct_val.cfgr = *cfg;
    if (!(struct_val.bits.enable == 0) && (!(struct_val.bits.mode==3)) && (struct_val.bits.reserved==0))
        return 1;
    else
        return 0;
}

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

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

    return 0;
}