Pack Multiple Fields into a 16-bit Control Register

Code

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

#define mode_mask       0x07
#define mode_pos        0
#define speed_mask      0x1F
#define speed_pos       3
#define reserved_mask   0x03
#define reserved_pos    8
#define status_mask     0x3F
#define status_pos      10

#define SET_PACK(reg, mask, pos, val)   (reg & ~(mask << pos)) | ((val & mask) << pos)

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

    reg = SET_PACK(reg, mode_mask, mode_pos, mode);
    reg = SET_PACK(reg, speed_mask, speed_pos, speed);
    reg = SET_PACK(reg, status_mask, status_pos, 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;
}

Solving Approach