Macro-Based Register Config Helper

Code

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

// Define macros here
#define ENABLEMASK  0x0001
#define MODEMASK  0x0003
#define SPEEDMASK 0x0007

#define ENABLE(VAL)  ((VAL & ENABLEMASK) << 0)
#define MODE(VAL)  ((VAL & MODEMASK) << 1)
#define SPEED(VAL) ((VAL & SPEEDMASK) << 3)

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);
    reg |= MODE(mode); 
    reg |= SPEED(speed);
    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;
}

Solving Approach