FPGA Replay Board

[freqmax]

The FPGA is the magic pill
It allows you to phase lock, manipulate bit-by-bit in realtime etc.

I think the big machines to really implement is A500 and A1200 which I suspect are the ones that are most widespread. The rest has to be configure your setup and pray (tm).

And the talk about how hard it is to code for all weird combinations of hardware is just a limitation of the number of willing coders. But with a baseline to work with it's way easier. It's easier to improve a specific chip to do something than to have to create a whole system from scratch as when you do that you have no working startpoint to work from. But rather have to make a theory and try.

[matthey]

xxx MHz enhanced 68020 FPGA mode - single cycle as much as possible, cache, ~100MHz
xxx MHz 68060 (>100MHz) or until it blows up.

Yee Haw! Now you're talking. Have you worked on or planned for a superscaler core? Will you put 64 bit integer instructions back in the 68060? Do you plan on adding any enhanced instructions or addressing modes? How about an FPU? Some demos use the FPU you know .

[Hattig]

Yee Haw! Now you're talking. Have you worked on or planned for a superscaler core? Will you put 64 bit integer instructions back in the 68060? Do you plan on adding any enhanced instructions or addressing modes? How about an FPU? Some demos use the FPU you know .

I'm sure these things will come along in good time - especially on the open source cores.

First up though I think we'd all be happy enough with a fast-as-possible '020 compatible core (as that's the easiest thing to create), then the cycle exact 68k (A500) and 68020 (A1200).

[matthey]

@Hattig
I agree that a stable and debugged 68020 compatible core is the priority but it's much easier to implement what has previously been planned for when programming. That is why I think a standard for 68k enhancements should be worked on now, which I have been doing. It's too late when everyone has conflicting and incompatible enhancements.

[jackflash]

I have been considering experimenting with fpgas, what software would I need to create my own core for the fpgaarcade? Is there a good beginners guide I could use to get started?

[freqmax]

Regarding add-on board. A board with (PLCC/DIP) sockets for Amiga custom chips to run synchronized with the core to debug could be useful for any core coders to straighten out any remaining compatibility.

[JimS]

I have been considering experimenting with fpgas, what software would I need to create my own core for the fpgaarcade? Is there a good beginners guide I could use to get started?

The FPGA on the fpgaarcade is a Xilinx Spartan 3. You can get Xilinx's design software free from them. Either download it... but have lots of time, it's over 4GB, or get a free DVD, which also takes time. ;-)
XESS - makes some Spartan-based development boards. They have some free tutorials on their web site.

[psxphill]

That is why I think a standard for 68k enhancements should be worked on now, which I have been doing. It's too late when everyone has conflicting and incompatible enhancements.

I actually think there should be no effort put into enhancing the 68k beyond what Motorola did. Potentially a CPU that does everything that an 020 to 060+68882 can do. But I wouldn't care if it's just an 060 that only supported the instructions an 060 did, it doesn't even need to be superscalar if the instruction rate was good enough.

[matthey]

I actually think there should be no effort put into enhancing the 68k beyond what Motorola did. Potentially a CPU that does everything that an 020 to 060+68882 can do. But I wouldn't care if it's just an 060 that only supported the instructions an 060 did, it doesn't even need to be superscalar if the instruction rate was good enough.

Why? If you are satisfied with a slow retro experience then you can use the 68000 or 68020 cycle exact cores. Motorola did enhance the 68k beyond the 68060 (in some ways) with the ColdFire. Instructions like MVS/MVZ and BYTEREV would have been *very* beneficial on the 68060 and the support can easily be enabled in compilers. A 5-15% speed increase and a 5-15% code reduction should be possible for new code with a negligible difference in speed (parallel fpga use) or compatibility of old code. The only worry is that the core grows too big but a simpler standard could be met that would fit but still provides a nice benefit. If we developed this, it could attract the attention of developers (embedded use) and there is a possibility of a return to a hard chip/ASIC in the future. The 68k has an industry leading ease of use and code density even today. It can be even better and modernized to compete with other modern processors.

If you have any technical knowledge of x86, ARM, PPC, or 68k then you will appreciate some great ideas in this enhanced 68k ISA:

http://www.heywheel.com/matthey/Amiga/68kF_PRM.pdf

[kolla]

Indeed, m68k is far from dead in embedded. The gnu toolchain and linux kernel gets lots of updates from companies that do commercial embedded solutions using m68k, there are several commercial FPGA implementations of m68k etc. Extending m68k beyond 060 is just great. What is the legal status of the m68k architecture compared to ARM and MIPS?

[billt]

The FPGA on the fpgaarcade is a Xilinx Spartan 3. You can get Xilinx's design software free from them. Either download it... but have lots of time, it's over 4GB, or get a free DVD, which also takes time. ;-)
XESS - makes some Spartan-based development boards. They have some free tutorials on their web site.

The WebPack version of ISE is free cost, but you do need to sign up for a license to be able to use it. Just so people aren't confused at the end of install and first run, the free WebPack license is needed at that point.

[Fats]

XESS - makes some Spartan-based development boards. They have some free tutorials on their web site.

Another provider of FPGA boards is Digilent Inc.. They have also some example projects for the Xilinx FPGA development environment using their boards.
Another one is Terasic.

[JimS]

The WebPack version of ISE is free cost, but you do need to sign up for a license to be able to use it. Just so people aren't confused at the end of install and first run, the free WebPack license is needed at that point.

True... I neglected to mention that.

[JimS]

Another provider of FPGA boards is Digilent Inc.. They have also some example projects for the Xilinx FPGA development environment using their boards.
Another one is Terasic.

I read that the folk at Elektor magazine will have their own FPGA board soon. From the pic it looks similar to the Xula board from XESS. I bet the minimig core could fit into the Xula2, if there are enough i/o pins... still saving my pennies for the Replay. ;-)

[matthey]

Indeed, m68k is far from dead in embedded. The gnu toolchain and linux kernel gets lots of updates from companies that do commercial embedded solutions using m68k, there are several commercial FPGA implementations of m68k etc. Extending m68k beyond 060 is just great. What is the legal status of the m68k architecture compared to ARM and MIPS?

This is the classic answer by the Natami creator:

In the Amiga world people get sued out of fun. But in the real world to which Freescale belongs people get sued only for money.
 
 It is only a nice story when Gunnar tells that we had a conversation with the ColdFire/M68k Division Manager of freescale. That we asked him if a custom made MC68060 with higher speed than the classic ones could be available. When he declined we got on asking if we could at least get/license some source HDL code to use in an FPGA. He told us that the MC68060 is built in some kind of HDL source. He regrets but it is absolutely not possible to get/see/license this code for anybody in any form. The only thing he could do is to provide us contacts to companies who sell 68k IP cores. Freescale itself doesn't do this, it is not their business. Then Gunnar asked him what might happen if we wrote our own IP. He said that Freescale will not have a problem with that and that, in his opinion, we do not need any permission from Freescale even if we are about to sell it. But we can not expect any technical help or support from Freescale when we decide to do so.
 
 This is just a story which happened some time ago. We do not need prove or evidence of that. This only (sadly) shows that this is the end of the road for the 68k. The business of this division of Freescale is to sell competitive embedded ColdFire chips, not software. These chips *must* not compete with faster PowerPC which is a different division at Freescale. As said, in the real world they would only sue us for money, not for fun. It would be money if we decide to sell 68k compatible chips running at 600MHz at a price of 1,5$ per piece. Then the discussion here might be justified. But it is not because we won't because we can't.
 
 I just wonder why AMD is still selling x86 compatible CPUs. Ah, right, I forgot. They use a completely different opcode than intel.
 
 Meaning that it might be worth continuing this discussion. Since we AND Freescale are not really involved because both do not have a problem with this topic I would emphasize to discuss whether an opcode is copyrightable or patentable in talk, not as an NatAmi question. For now Freescale does not have any interest in high-speed 68k. The moment this changes we are the first to get a 2GHz 68k dual core and just drop the softcore '50 (sorry Gunnar/Jens) and get the chip mounted onto a SyncZorro card. But immediately.

[freqmax]

In court what says is invalid. What counts is written agreement.