25. Pack Multiple Fields into a 16-bit Control Register

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

uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    uint16_t packed_register = 0U;
    packed_register |= ((mode & 7) << 0);
    packed_register |= ((speed & 31) << 3);
    packed_register |= ((status & 63) << 10);

    return packed_register;
}

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;
}