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Message
From: H. Peter Anvin<hpa@z...>
Date: Thu Nov 10 06:58:41 CET 2005
Subject: [oc] T80 bugfix for INI, IND, INIR, INDR, OUTI, OUTD, OTIR, OTDR
MikeJ wrote:
> I did a lot of the debug work on the t80, and am maintaing the T80 & T65
> cores at www.fpgaarcade.com.
> Let me know if there are any bug fixes I have not merged yet.
> I will push them back to opencores at some point.
> /Mike
>
Hi there,
I looked through your stuff, and it looks like you have most of the same
stuff; you have a different Auto_wait fix than I have, but they probably
both work.
Something I added is a RETI# output; this is not in the original Z80, of
course, but since the latter used bus snooping to detect RETI#, and bus
snooping is a bit painful to do in a typical FPGA/ASIC environment
without tristate busses, I decided the cleanest way to signal RETI is to
have another output on the CPU -- the synthesizer will optimize it out
if it's not used.
My code is part of the ABC80 FPGA project
(ftp://ftp.abc80.org/pub/fpga/abc80/) -- it also contains a PIO design
in Verilog. Since the rest of the project is in Verilog I'd like at
some point to switch it over to the TV80 core, but I haven't been able
to yet because of the JR bug.
-hpa
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