[rescue] Total corporate madness (

Joshua D. Boyd jdboyd at celestrion.celestrion.net
Thu Aug 7 11:24:56 CDT 2003

On Thu, Aug 07, 2003 at 11:09:58AM -0500, Scott Newell wrote:
> >BTW, have you looked at the Hitachi H8?  25mhz 16/32 bit risc, built in
> I'm curious--what about the H8 series would you describe as riscy?  I've
> only used the H8/Tiny, so I'm not up on some of the higher end models, but
> I see: lots of addressing modes, variable length instructions, instructions
> that execute in various clock cycles, a few decimal adjust instructions,
> and multiple/divide instructions.

I generally have two theories of what constitutes RISCy.  Instictively,
if it is a fairly strict load/store architecture, I tend to think RISC.
Looking at the H8/3024 manual, I see that the only instructions that can
use memory are the bit manipulation ones, and the movs, stack
instructions, and LDC/STC.  So, technically, this might not define RISC,
when I see it, I think RISC.

I guess that variable instruction length doesn't suggest RISC though.
I'm not positive (and I don't have the time now to be positive), but I
thought that on the chips we were looking at that most, if not all, the
instructions were 16bit.  Could be wrong.  I was mainly going by the
load/store anyway.

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