Very nice.
I'm not up with the due yet ( ordered and waiting ), the two ports A & C, I'm assuming are 32-bits wide. If this is the case, does this mean there is around 40 unused pins?
If so are they usable, I'm thinking along the lines of 'probably not' without changing the single write to a mask of bits. Maybe the due has someway of dealing with this.
I'm just wondering as there only appears to be a few port B and D pins left without A & C.