[libre-riscv-dev] KCP53010 Updates

[Samuel Falvo II]

I've decided not to abandon the processor.

Instead, I've decided to restart it from scratch, but this time with a
monolithic IXU (Integer Execution Unit), built 6502- or Z80-style.  It's
occurred to me that it's not only easier to get working up front, but if my
hunch is right, all the explicit X0..Xn and F0..Fn states (which you can
see in the KCP53000 sources) correspond *almost* one to one to the various
GO_xyz signals in a scoreboard-driven design.  IOW, what I'm trying to say
is, it'll be easier to adapt an existing IXU to a scoreboard design later,
than it will be to build a new one from scratch now.  *IF* my hunch is
right.

I *have*, however, decided to abandon TileLink.

Not that I dislike it, but Wishbone has a few advantages over it which I
think would reduce the burden of building out the processor logic going
forward.

-- 
Samuel A. Falvo II