#include <stdint.h>

int main()
{
    union {
        uint32_t cw            : 13;

        struct {
            uint32_t setting4  : 4;
            uint32_t cmd       : 9;
        };

        struct {
            uint32_t setting8  : 8;
            uint32_t cmd       : 5;
        };
    } control;

    return 0;
}