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_mode = (mode & 0x07U);    
    uint16_t packed_speed = (speed & 0x1FU) << 3; 
    uint16_t packed_status = (status & 0x3FU) << 10;
    return packed_mode | packed_speed | packed_status; 
}
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;
}