Pack Multiple Fields into a 16-bit Control Register

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

#define MODE_POS 0
#define SPEED_POS 3
#define STATUS_POS 10

#define SET_MODE(reg, mode) (reg |= (uint16_t)(mode << MODE_POS))
#define SET_SPEED(reg, speed) (reg |= (uint16_t)(speed << SPEED_POS))
#define SET_STATUS(reg, status) (reg |= (uint16_t)(status << STATUS_POS))
uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    // Your logic here
    uint16_t ans = 0;
    SET_MODE(ans, mode);
    SET_SPEED(ans, speed);
    SET_STATUS(ans, status);
    return ans;
}

int main() {
    uint8_t mode, speed, status;
    scanf("%hhu %hhu %hhu", &mode, &speed, &status);

    uint16_t reg = pack_register(mode, speed, status);
    printf("%u", reg);
    return 0;
}