Linked by Thom Holwerda on Thu 2nd Mar 2006 12:24 UTC, submitted by Timothy Miller
3D News, GL, DirectX The Open Graphics Project is dedicated to producing open-architecture graphics hardware that is friendly to free and open source operating systems like Linux and BSD. Yesterday morning, they released schematics for OGD1 for public review and critique. OGD1 is an FPGA-based development and prototyping platform that they decided to turn into a commercial product to raise funds. Check out an article on KernelTrap. The release of these schematics was accompanied by a discussion about how to price the OGD1 to maximize fund-raising while keeping it accessible to hobbyists; KernelTrap has another article about that as well.
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RE[2]: OGP PCI core
by theosib on Fri 3rd Mar 2006 21:08 UTC in reply to "RE: OGP PCI core"
theosib
Member since:
2006-03-02

I have considered making the PCI core GPL rather than LGPL. This way, if you use it under GPL, you have to open source your entire design. If you don't want that, you can buy a commercial license. I'm pondering it, and I have mentioned it on OGML.

I did a PCI 64/66 design on an ASIC back in 2000. This ASIC was slower than the FPGA we're using here. On top of that, I've gotten better as a chip designer. I think 133MHz is probably doable. If not, it'll make it just fine in the ASIC, where that speed is important for the PCIe-to-PCIX bridge.

It's important to minimize your internal combinatorial delays. Often a harder problem is keeping your external I/O's fast. If it all possible, always use the register in the I/O buffer. The Opencores PCI design separates the PCI target and master logic and then multiplexes that together at the I/O buffers (it looks like to me from the diagrams). I've decided to merge the master and target state machines so that they implicitly share the I/O's, so we can always use the registers in the I/O buffers for output. I've played other tricks to ensure that inputs are handled well also.

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