Pack Multiple Fields into a 16-bit Control Register

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

#define MODE_BIT(reg, value)       reg |= (value << 0)
#define SPEED_FIELD(reg, value)    reg |= (value << 3)
#define RESERVED_FIELD(reg, value) reg |= (value << 8)
#define STATUS_FIELD(reg, value)   reg |= (value << 10)

uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    // Your logic here
    uint16_t reg  = 0;
    MODE_BIT(reg, mode);
    SPEED_FIELD(reg, speed);
    RESERVED_FIELD(reg, 0);
    STATUS_FIELD(reg, status);

    return reg;
}

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;
}