Pack Multiple Fields into a 16-bit Control Register

Code

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

uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    #define MODE_POS 0
    #define MODE_MASK 0x7
    #define SPEED_POS 3
    #define SPEED_MASK 0x1f
    #define STATUS_POS 10
    #define STATUS_MASK 0x3f
    
    uint16_t reg;
    reg |= (mode << MODE_POS) & (MODE_MASK << MODE_POS);
    reg |= (speed << SPEED_POS) & (SPEED_MASK << SPEED_POS);
    reg |= (status << STATUS_POS) & (STATUS_MASK << STATUS_POS);

    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;
}

Solving Approach