XMOS chips and the FPGA Arcade Replay

[psxphill]

Hmm.....as opposed to unwillingly programmed?
 
These chips are programmable.....but only once....hence the discussion to use a chip socket when you want/need to update your device.....This same concept is used to update classic Amigas with updated Kickstarts. So what's the problem?

The 4 core version has 64k of ram and 28 i/o pins, it wouldn't even be able to emulate a c64. The most expensive one ($27.11) has 256k ram & 256 i/o pins, which is starting to get better. I don't know if you can run code from ram, but it only has 32k of otp rom. I'm not convinced you could emulate a c64 on that either but I don't mind being proved wrong.
 
Feel free to discuss it somewhere else, but if all you're going to do is drool over it and not actually try building something with it then you're just wasting your time. It has absolutely nothing to do with the FPGA replay & cannot possibly emulate an Amiga.

[psxphill]

Who is drooling? I just stated that if people wanted to consider using an inexpensive but fast, write-once programmable chip that they should consider using a socket. I never mentioned C64s, pins or anything else. You're as bad as ChaosLord when it comes to making assumptions and being difficult! That's one of the reasons why I rarely post here because guys like you and ChaosLord have turned this board into a digital freak-show that you use to bully and push other people around to satisfy your massive cases of overgrown ego.

My point was that it's pointless to use it in any way with an FPGA Arcade, the original thread was purely about the FPGA Arcade and this thread implies discussion about it's use with the FPGA arcade. Other people had mentioned using it for emulation, you incorrectly assumed that this part of my post was directed at you.
 
You would only use one of those in mass produced equipment where you wouldn't need to do an update. It's a pretty unexciting chip, I'd rather pay the extra and get a chip that could run different software without throwing it away. By the time you've run 100 different programs on it, the chip has worked out very expensive.

[psxphill]

That's not true. There are already a few microcontroller based C64 emulations. The specs for this chip with its 4 cores could easily emulate the C64 if you added some external RAM.

I wouldn't have thought there would be enough I/O pins for ram after you've added joysticks, keyboard, display, sound & some storage. Unless you used serial for everything and added a bunch of custom external glue. This defeats the point as the cost starts going up & then you might as well use one of their more expensive chips.
 
I would guess they do development versions of these, even if it's a OTP loader and you test you code running from ram. Some older OTP chips were internally just eproms but with no erase window, if that is the case here then development ones might just come with a window. There is no way anyone would be able to do anything with them if you have to throw a chip every time you make a change. Development versions will be more expensive though.

[psxphill]

How much does the reprogrammable XMOS cost? and is the same specification?

They don't appear to offer one. It appears you can run code from ram, they have an OTP module that loads data from encrypted SPI flash http://www.xmos.com/products/why/dsp
 
You might be able to do it via JTAG without programming the OTP. Or you could program the OTP with your own simple loader that allows programs to be uploaded to flash. As long as you can reset it externally then you can run whatever you want and whenever you want.
 
However I still don't think the $3 one is worth bothering with. You'd be wanting to look more towards the $25 dollar one to make it worthwhile. They also do ones with usb interfaces, which would also be interesting as then it wouldn't be limited to the FPGA Arcade. Their debug adapter appears to use an xcore itself http://www.xmos.com/products/xkits/debug

[psxphill]

At that point you are better off with a couple of 100MIPs ST32 micros at $5.00 each... Lots of code space, RAM, I/OS.

Yes, that was my point. Not that having an additional processor is a bad thing, but having the $3 xmos is pointless for what we'd use it for.
 
Using the $99 dollar xcore development board would be insane, unless you're looking to mass produce something that will fit on it (I think the development boards use the more powerful chips anyway though).

[psxphill]

what is the point of having foreign coprocessor on amiga/clone?

It's not an Amiga clone though, it can emulate anything.
 
The idea of using additional processors would be to reduce the strain on the fpga. So if you needed mp3 decoding you could offload that to another chip.
 
I'm not saying I think it's a good idea, put that is the point.