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) {
    /* vaidate inputs */
    if (mode > 0b111) mode = 0b111; 
    if (speed > 0b11111) speed = 0b11111;
    if (status > 0b111111) status = 0b111111; 

    uint16_t res = 0; 
    res |= (mode << 0) | (speed << 3) | (status << 10); 
    return res;
}

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;
}