23. Set Baud Rate Field in Control Register

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

uint32_t set_baud_rate(uint32_t reg, uint8_t baud) {
    uint8_t mask = reg & 0xFF;
    baud <<= 4;
    reg &= ~((1U << 12) - 1);
    reg >>= 4;
    reg |= baud;
    reg <<= 4;
    reg |= mask;
    return reg;
}

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