65c02 VHDL/Verilog core

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dominicbeesley
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65c02 VHDL/Verilog core

Postby dominicbeesley » Fri Feb 16, 2018 11:49 am

Hello,

I'm about to send off my latest (blit/dma/cpu/sound) board for fabrication and was wondering how to test this in a master. In the beeb I've tended to first bring these up using a VHDL core (T65) which works well and I'm familiar with. However, I know that the T65 core is incomplete and doesn't support all the 65c02 instructions - what I'm not sure of is how incomplete? i.e. would it cover the cmos instructions used in BASIC 4 and the MOS?

Are there other cores for 65C02 or 65816 operation that I've not spotted? I last looked a few years ago but settled on the T65 as the least troublesome but I didn't know Verilog (or much VHDL) then...

If not I'm in danger of being dragged down another rabbit hole and try and add the extra instructions to the T65 which would be a bit of a detour given that I don't really know the 65C02!

If not it is not a big deal as this board will have a connector for a _real_ cpu which could be used instead but I would need to rework my test benches...

TIA

D

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hoglet
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Re: 65c02 VHDL/Verilog core

Postby hoglet » Fri Feb 16, 2018 12:26 pm

I know of two reasonable 65C02 cores:

In 2016 BigEd and I added the 65C02 instructions to Arlet's 6502 core:
https://github.com/hoglet67/CoPro6502/t ... /src/Arlet

There is also AlanD's 65C02 core:
https://github.com/hoglet67/CoPro6502/t ... /src/AlanD

Both of these are well tested, having been used in the Matchbox Co Pro at some point.

As far as I remember, they both pass the Dormann tests. Neither implement the Rockwell/WDC specific extensions (RMB/SMB/BBR/BBS).

If you are using Arlet's core with asyncronous RAM, you need to add external registers to the A, Dout and RnW signals.

Dave

dominicbeesley
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Joined: Tue Apr 30, 2013 11:16 am
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Re: 65c02 VHDL/Verilog core

Postby dominicbeesley » Fri Feb 16, 2018 3:26 pm

Thanks Dave, these both look the part! I'll have a play and report back if I ever get time to finish this board!

D