* how about for setting the OUTSET bits? I have this currently attempting to set 21 and 28:
    let p\_outset = (0x5000\_0000 + 0x508) as \*mut u32;
    unsafe {
        \*p\_outset |= 1 \<\< 20; // row1
        \*p\_outset |= 0 \<\< 27; // col1
    }