[TomVDB]

Many years ago, we had a custom made board with 8 huge Xilinx Virtex 5 FPGAs (the largest available at the time) to emulate a large SOC. Those FPGAs were something like $20K a piece.

We had 10 such boards, good for millions of dollars in hardware, and a small team to keep it running.

These platform were mostly used by the firmware team to develop everything before real silicon came back. It could run the full design at ~1 to 10MHz vs +500MHz on silicon or 10kHz in simulation.

After running for a while, that FPGA platform crashed on a case where a FIFO in a memory controller overflowed.

Our VP of engineering said that finding this one bug was sufficient to justify the whole FPGA emulation investment.

[jacquesm]

Design verification is big business and your VP was exactly right, a factor of 100 to 1000 speed increase would allow for much more thorough testing and broader testing as well, for instance hooked up to other hardware with reasonable fidelity compared to the real thing. Still coarse but a lot better than nothing. Good call. It isn't rare at all to have a respin if you don't do design verification.

One of the nicer stories about the first ARM chip is that they built a software simulator to verify the design and as a result they found plenty of bugs in the hardware before committing to silicon. The first delivered chips worked right away.

[mindentropy]

The multiple FPGA on a board is generally from Dini Group right? Fantastic boards.

Ref: https://www.dinigroup.com/web/index.php

[duskwuff]

Dini's naming schemes are hilarious. They're all named like monsters in B-movies -- their latest system, the DNVUF4A, is called "Godzilla's Butcher on Steroids", for instance.

Also, Dini got acquired by Synopsys a few years ago.

[mindentropy]

Oh I love their humor. There is always something humorous written for their status LEDS.

"Although no specific testing was performed, sophisticated statistical finite element models and back of the envelope calculations are showing the number of status LEDs to be bright enough to execute dermatological procedures normally done with CO2 lasers. Contact the factory for more information about this sophisticated feature and make sure an adult is present during operation. These LEDs are user controllable from the FPGAs so can be used as visual feedback in addition to burning skin."

"As with all of our FPGA-based products boards, the DNVUPF4A is loaded with LEDs. The LEDs are stuffed in several different colors (red, green, blue, orange et al.). There are enough LEDs here to melt cheese. Please don't melt cheese without adult supervision. These LEDs are user controllable from the FPGAs so can be used as visual feedback in addition to the gratifying task of creating gooey messes."

[iron2disulfide]

There are a lot of companies who create multi-FPGA boards. The market for FPGAs-for-ASIC-prototyping is substantial.

[TomVDB]

No, it was in-house custom made for the purpose.

Huge PCBs, ~2ft by 2ft.

[mindentropy]

Curious, what was the reason for going with custom board instead of COTS boards?

Is board to board connection with high speed connectors feasible? This was what I heard from verification folks.