Set Specific Bits in a 32-bit Register

Code

uint32_t set_bits(uint32_t reg, uint8_t pos, uint8_t len) {

    // If pos is outside 0–31, do nothing
    if (pos >= 32)
        return reg;

    // If len is zero, nothing to set
    if (len == 0)
        return reg;

    // Clamp len so we don't exceed 32-bit width
    if (pos + len > 32)
        len = 32 - pos;

    // Create mask safely
    uint32_t mask = ((1u << len) - 1u) << pos;

    return reg | mask;
}

Solving Approach