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

#include <stdio.h>
#include <stdint.h>
#define MODE_BITS_MASK 0X7
#define SPEED_BITS_MASK 0X1F
#define RESERVED_BITS_MASK 0XFCFF
#define STATUS_BITS_MASK 0X3F
uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    // Your logic here
    uint16_t reg=0;
    reg|=(mode & MODE_BITS_MASK);
    reg|=((speed & SPEED_BITS_MASK)<<3);
    reg|=((status & STATUS_BITS_MASK)<<10);
    reg&=RESERVED_BITS_MASK;
    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;
}