MinSoC support even more boards (http://opencores.org/project,minsoc) but there are less supported peripherals there. Ethernet and UART IIRC
The cheapest ones are about $50 or $60. Think the de0-nano is cheapest
If you want to try out some OpenRISC developing without having to buy a dev board, there is also the OpenRISC architecture simulator or1ksim http://opencores.org/or1k/Or1ksim It supports UART through xterm or telnet, ethernet with TUN/TAP and a framebuffer
Or simply the dude who did it owned a DSP1800 as opposed to the board I have at home?
You're actually spot on
I think it was a tight fit though, so I'm not sure it will fit on smaller spartan 3 FPGAs. Disabling caches and hardware mul/div and stuff like that could help. It's a pretty common board, so if anyone is interested in trying, just drop in to #opencores on freenode and chat with us
CPU implementations, in this case, are far from what they could be. Why is there not an open source equivalent of ARM's processors in the way that the Linux kernel was developed due to a lack of other open OS kernels? There's actually a couple of good reasons, but none should be terminal to the idea.
I'm working on the OpenRISC project. That is 100% LGPL and with Linux 3.1 it will be supported in the mainline kernel (along with an ever increasing support for different RTOS's). We are slowly getting there
Timing errors are always the hardest things to track down. Fortunately we are talking about a fully digital ASIC with one clock domain, except for the memory controller, and some other things I might have ignored. I recently finished a project where we converted a FPGA to an ASIC that had more than 180 clock domains. That, my friend, was hard.
The logic bugs are mostly tracked down in simulation, and on the FPGA prototypes. Remember that the openRISC CPU has been available for some time already, runs Linux 2.6.38 fine and is being used in the industry. The RTL is mostly done except for ASICification of some parts.
The fear of suppliers running out of MCUs is real, I can tell you. Reverse-engineering of chips, and reimplementation in FPGA happens all the time in the industry. It is expensive and time-consuming, so having the source code and constraints around is a big help.
If your order volume is small, the fixed costs will eat you alive.
...which is why opencores is asking for donations
There is a block level view of what's going in, which is mostly off-the-shelf OpenCores cores, but there are no detailed plans about how this is going to be translated into an actual ASIC design.
1. Push ASIC button
There are only plans for making a FPGA based development platform.
Don't get me wrong, a FPGA platform is a good thing to do. A project like this won't have the resources to do very much design validation through simulation (which requires lots of people writing tests and running sims, i.e. real money), so FPGA based prototyping and validation is even more important than it is for conventional "closed source" ASIC projects. However, there is no plan given for how they're going to take their working FPGA design and turn it into an ASIC design.
Verification is always the largest issue when you are building complex systems. One of the benefits of open source however, is that someone might have done it before you. In the case of the OpenRISC CPU, the 80000 (correct me if I'm wrong) regression tests of GCC is being used as one source of verification stimuli. Keep in mind also that the design isn't being created from scratch. The core is about ten years old
It's somewhat revealing that they're using a single small Altera Cyclone IV FPGA (under $60 qty 1 through Digikey). If you don't understand the significance, this means their design is tiny and trivial and low tech by current standards.
This isn't an effort to create the next-generation-273-bit-mega-hyper-threaded-with-DDR-5-and-379-core-subpixel-shader-gpgpu on crack. It's a fairly standard 32 bit RISC SoC, with the main difference that the RTL code is open source, and that the ASIC will be sold at a low cost even in low quantities. Think of how popular the Arduino platform is for example. It has some extra street cred, because the layout is open source. Now this is taken one step further, by using a LGPL:d CPU and peripherals. The quaking-in-their-boots part sounds a bit exaggerated, but still, it is primarily because this hasn't been done before. And if it turns out good, there is an ASIC proven SoC that can be modified and recreated by anyone that doesn't want to pay an ARM or a MIPS license for a 32-bit RISC system. Also, by using a fairly cheap FPGA, a reference board with either the ASIC or the FPGA can be sold at a reasonable cost.
"I never let my schooling get in the way of my education." -- Mark Twain