Macro-Based Register Config Helper

Code

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


unsigned int  reg = 0b0000000000000000;    

#define enable_bit_pos     0
#define enable_bit_len     1

#define mode_bit_pos       1
#define mode_bit_len       2

#define speed_bit_pos      3
#define speed_bit_len      3
     
#define set_fields(reg, pos , len , value)\ 
 reg = reg & ~((((1<<len)-1)<<(1<<pos))) | ((((value) & (1<<len)-1)<<pos)) 

// Define macros here

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    set_fields(reg, enable_bit_pos , enable_bit_len , enable);
    set_fields(reg,mode_bit_pos,mode_bit_len,mode);
    set_fields(reg,speed_bit_pos,speed_bit_len,speed);
    
    
    
    
    // Use macros to set fields
    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