FPGA for dummies

[mongo]

Thanks Fats,

I am a little surprised that more people have not researched XCore and the XMOS chips in detail, since they are included in the newest flagship of the AmigaOne line.

I know not everyone can afford one, but I thought maybe some of the X1000 beta testers could comment on what the XMOS chips is and what it can and cannot do, without infringing on their NDA's with A-Eon.

Just a general statement or two about how they differ from FPGA's, since both appear to be programmable chips.  One using VHDL, or Verilog and the other using the "C" language with X extensions to program them.

I guess the people that know are too busy to be reading this thread.  I will have to do more research on my own, but was hoping one of the experts would chime in.

Where are you Steve Solie?  You might not be an expert on XMOS, but I'll bet you can shed some light on my questions.

The XMOS chip is a CPU. It contains no programmable logic and is nothing at all like a FPGA.

[Thorham]

The XMOS chip is a CPU. It contains no programmable logic and is nothing at all like a FPGA.

Indeed, even though it says this on their site:

XMOS embedded processors bring together the capabilities of processors, DSPs, ASICs and FPGAs in one, two and four core devices. Find the right chip for your designs.

Very misleading after you read about what those chips really are, on the same site :hammer:

[wawrzon]

Thanks Fats,

I am a little surprised that more people have not researched XCore and the XMOS chips in detail, since they are included in the newest flagship of the AmigaOne line.

I know not everyone can afford one, but I thought maybe some of the X1000 beta testers could comment on what the XMOS chips is and what it can and cannot do, without infringing on their NDA's with A-Eon.

Just a general statement or two about how they differ from FPGA's, since both appear to be programmable chips.  One using VHDL, or Verilog and the other using the "C" language with X extensions to program them.

I guess the people that know are too busy to be reading this thread.  I will have to do more research on my own, but was hoping one of the experts would chime in.

Where are you Steve Solie?  You might not be an expert on XMOS, but I'll bet you can shed some light on my questions.

speaks lengths about how much it is worth, anticipated and generally demanded, especially on amiga related hardware, doesnt it? i would steer clear as far as possible. there is troubles enough without it.

[amigadave]

The XMOS chip is a CPU. It contains no programmable logic and is nothing at all like a FPGA.

Please elaborate!

That is not what I came to understand from my short read of their site, but then I am here asking for clarification, because I am not sure exactly what they are.

Are you saying that they are nothing more than a specialized CPU that runs modified "C" code?

At Wawrzon, I disagree.  Just because no one in the Amiga community has looked at these chips long enough to come up with a useful purpose yet, it does not mean that it won't happen.

The company would not still be in business if they were not producing something useful.  It is hard enough to stay in business when you make something that is useful and there are many examples on their site showing what the chip is capable of.  One item in particular that interested me (as an iPhone owner), is the iPhone dock that uses the exact same XMOS chip that is on the X1000 motherboard.

[trekiej]

Can't we all just get along?
1400!

[psxphill]

It won't emulate, simulate, run any code or anything else. All that is plain misunderstanding.

It doesn't run code, but you can emulate or simulate something with an fpga. Emulation/simulation doesn't require you to use a sequential programming language running on a cpu.

[Thorham]

It doesn't run code, but you can emulate or simulate something with an fpga. Emulation/simulation doesn't require you to use a sequential programming language running on a cpu.

You're not saying it right: An FPGA provides the user with an environment which enables the user to implement electronic circuit designs without having to build a physical implementation for each design. That's why it's an emulation.

Sorry, couldn't help my self

[mongo]

Please elaborate!

That is not what I came to understand from my short read of their site, but then I am here asking for clarification, because I am not sure exactly what they are.

Are you saying that they are nothing more than a specialized CPU that runs modified "C" code?

It's a CPU that supports 8 threads per core. It doesn't run C code, at least not directly. You have to compile your programs with their version of GCC. XC is a version of GCC that has extensions to support multi-threading and possibly some of the other hardware on the chip.

[persia]

@wawrzon

For bout 100 bucks you can find out what an XMOS does. It's basically a small computer you can program and place in remote situations.  If you have a robot for example, you program the XMOS chip to run your robot and plug it into the robot.  It's cheap and efficient.

[Bif]

Thanks Fats,

I am a little surprised that more people have not researched XCore and the XMOS chips in detail, since they are included in the newest flagship of the AmigaOne line.

I know not everyone can afford one, but I thought maybe some of the X1000 beta testers could comment on what the XMOS chips is and what it can and cannot do, without infringing on their NDA's with A-Eon.

Just a general statement or two about how they differ from FPGA's, since both appear to be programmable chips.  One using VHDL, or Verilog and the other using the "C" language with X extensions to program them.

I guess the people that know are too busy to be reading this thread.  I will have to do more research on my own, but was hoping one of the experts would chime in.

Where are you Steve Solie?  You might not be an expert on XMOS, but I'll bet you can shed some light on my questions.

I thought we already kind of covered the possibilities in a thread about a year ago and it seemed people that might have some inkling chimed in at the time, and nobody could really come up with any sensible use for it. Sorry to sound negative, but I think that's why you aren't hearing any real use for it being proposed.  

I'm just a software guy and I haven't looked at the XMOS in gory detail, but to me this just looks like a CPU that is good for wiring to other hardware and is particularly good at responding to multiple events with low latency, better than a general purpose CPU for that. But it's also nowhere as fast as a general purpose CPU.

If it served as the main CPU for some bit of electronic hardware it can probably do the intended job for a decent price. But sticking it inside a computer where there's already a powerful CPU and IO slots? Doesn't make much sense to me at all. Sure, you could make it do something and make it interface to some hardware in the Xorro slot or whatever, but is this something that will work out better than what can be done with IO boards on a PC? I don't really know as I'm not a hardware guy, but it seems to me if XMOS was a great idea you could just plug a card into your PC or have one come on it's motherboard. Maybe you can, but I don't hear much about that there either as solving many of the world's problems.

[bloodline]

If I've read the xmos specs right, it should be pretty good at allowing you to implement at run time, all manner of I/O... I'm not sure what use that really has for the desktop hobbyist, but I can see how it would be very useful for hardware dev and small industrial production runs.

[Mizar]

I find this philosophical argument about Emulation vs Real hardware equity funny.

Either via a software emulator or an FPGA, there is a recreation of the original functionality of the old chips. Neither is more "real" than the other and both "emulate" (meaning: appear to be like the original hardware from a user and software perspective) the Amiga.

I've been having a laugh while reading this thread too.

Yes, either software emulation or FPGA recreates the original functionality.  However, only the FPGA recreates the original CIRCUITRY (and is actually more precise therefore).  We're only talking the internal makeup of the computer that makes it what it is and how it works here.  The DNA of the Amiga... as long as this is replicated how can this be called mere "emulation"?  This is definitely more "real" than just software emulation on an alien platform.  It's not emulation, it's cloning, if of an ephemeral nature due to the hardware being used.

And it's just semantics that some are using "emulation" in a broader sense, to include anything and everything that is not the original Amiga hardware.  If it has any difference in the technology of the hardware, if it doesn't have anything stamped on the chips that you can visually read it's a 68000/3.1 ROM/Denise/Agnus/etc., or that it doesn't have the original external case and look of the Amiga, then some insist it's not really an Amiga, just an "emulated" one.  And ignoring the fact that electronically it is identical!  Not original Amiga, but not emulated, that is actually a clone.  To use the word "emulate" for anything not original, is too confusing, inaccurate, and broad of a definition.

The comparison between RAM and ROM to FPGA and hard-wired chips is very accurate.  But consider another analogy: authentic English speaking or translated English.  One is the real deal, the other is not.  Translated can't have quite the precise same meaning as the original, much like emulation isn't precisely the same.  Someone Japanese speaks in their native tongue and a translator converts it to English.  This is like emulation.  Someone British speaks English, of the ethnicity of original English speakers.  This is the "real" thing.  Someone Japanese speaks English, born in the UK and has no Japanese accent.  Is this translated English (emulation), just because they're not of the original English speaking ethnicity, or is it "real" English?  It's the same thing as arguing the Japanese native-English speaker is translated English to argue the FPGA Amiga is emulating a real Amiga.  They're both doing the same exact thing, but they just LOOK different.  It's what's going on under the hood that matters most.

[JimS]

You're not saying it right: An FPGA provides the user with an environment which enables the user to implement electronic circuit designs without having to build a physical implementation for each design. That's why it's an emulation.

Sorry, couldn't help my self

Au Contraire, An FPGA gives the user an environment were the user *can* build a physical implementation of his design without all that tedious mucking about with a wire-wrap gun and a pile of chips. That's why it's not emulation.  

Sorry, coundn't resist either. ;-)

[persia]

And it's not really recreating the circuitry of the original chips, that's unknown, what it's actually doing is creating a "soft" circuitry that reproduces the results of most, if not all of the original "hard" circuitry results.

Yes, compared to modern hardware the Amiga custom chips are extremely simple, but still what you have is a simulation of what the Amiga was.

But why is this important?

[freqmax]

Gosh, there's no soft circuitry or simulation.

Either you have circuit that match the electrical and most importantly the timing specification. If that is fulfilled, it's the real deal.

[shoggoth]

Saying that FPGA isn't emulation because an FPGA is parallel or isn't programmed the same as a CPU is just plain stupid.

 
You clearly misinterpreted my comments, or didn't read them in their proper context. You have been claiming similarities between FPGAs and CPUs on the basis that they're both programmable devices, programmed using programming languages, and… other things which only makes sense if you disregard all technical facts about this matter. I wouldn't go as far as to call that, quote "plain stupid", but I'd definitely call it ignorant.

I've worked on a couple of very well known emulators, so I know what I'm talking about. Linking to wikipedia is more so I don't have to rewrite what they already said. kthx

I've implemented user land emulators and worked on a number of low level emulation frameworks, including semi-cycle accurate ones, which means I'm not entirely unfamiliar with the inner workings of emulators either. Other posters may very well know what they're talking about, even if their opinions about stuff differ from yours.

Just to make sure we understand each other. I don't claim to be an expert on VHDL and FPGA technology, but I have used it to implement several projects. For real. Now, that doesn't mean I'd use your words ("so I know what I'm talking about"), because that would be, quote, "plain stupid".

Problem here is about belief vs. technical facts, and since I'm not much of a believer I don't think I have anything more to add here, at least not to this particular part of the discussion.

kthx.