Macro-Based Register Config Helper

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

// Define macros here
#define ENABLE_POS   0
#define MODE_POS     1
#define SPEED_POS    3

#define ENABLE_MASK  0x1
#define MODE_MASK    0x7
#define SPEED_MASK   0xF

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    uint16_t reg = 0;

    reg |= (enable & ENABLE_MASK) << ENABLE_POS;
    reg |= (mode   & MODE_MASK)   << MODE_POS;
    reg |= (speed  & SPEED_MASK)  << SPEED_POS;

    return reg;
}

int main() {
    uint8_t enable, mode, speed;
    scanf("%hhu %hhu %hhu", &enable, &mode, &speed);

    uint16_t reg = build_register(enable, mode, speed);
    printf("%u", reg);
    return 0;
}