23. Set Baud Rate Field in Control Register

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

#define BAUD_SHIFT 8
#define BAUD_MASK  (0xFu << BAUD_SHIFT)

uint32_t set_baud_rate(uint32_t reg, uint8_t baud) {
    baud &= 0xF;                  // keep only 4 bits
    reg &= ~BAUD_MASK;            // clear baud field
    reg |= ((uint32_t)baud << BAUD_SHIFT);  // insert new baud
    return reg;
}

int main() {
    uint32_t reg;
    uint8_t baud;
    scanf("%u %hhu", &reg, &baud);
    printf("%u", set_baud_rate(reg, baud));
    return 0;
}