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 result = 0;
    uint8_t reserved = 0x03;
    result = result | mode;
    result = (speed << 3) | result;
    result = ~(reserved << 8) & result;
    result = (status << 10) | result;
    return result;
}
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;
}