Keil no longer has, if they ever did, a good grasp of what 805x means. They support the parts that don't diverge too much from "middle-of-the-road" spec's, and the try to lump together devices that shouldn't be lumped together.

From what their people have passed along to me, they don't seem to understand, very thoroughly, the differences between different device classes, and simply, willy-nilly, lump them together because they come from the same source, completely ignoring major differences.

From where I sit, that renders their entire product line unuseable, since one never knows when they'll just throw up their hands and say, "Well, we don't support THAT."

Now, getting SDCC going is also non-trivial if you don't use a "typical" 805x, but at least there's some hope. Now that ARM has "acquired" KEIL, I doubt there'll be any further expansion or bug fixes, since ARM would prefer that 805x would die. Their support, I believe, for new devices will stop entirely, and if it's not supported now, well, you're on your own. OTOH, if you follow SDCC, there's a good chance that a popular variant will get some support.

RE