Macro-Based Register Config Helper

Code

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

// Define macros here
#define ENABLE_POS (0)
#define ENABLE_MASK (0b1)

#define MODE_POS (1)
#define MODE_MASK (0b11)

#define SPEED_POS (3)
#define SPEED_MASK (0b111)

#define SET_REG_FIELD(x,val) (((val&x##_MASK)<<x##_POS)) 


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