Re:Open Source Needs FPGAs; FPGAs Need an On-Ramp
by pdelbarba on Friday March 31, 2017 @06:17PM
(#14008840)
Also worth noting that for real time control you can't beat the speed. Essentially, everything you do on an FPGA happens at the same time. You could see a 1000 line Verilog file that completes a huge operation in a handful of cycles.
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Re:Open Source Needs FPGAs; FPGAs Need an On-Ramp
by 0xcde4c3db on Friday March 31, 2017 @06:49PM
(#14009079)
Also note that "speed" includes latency, and not just low latency but also deterministic. You can do things like adjust a timestamp or tweak a control equation knowing that a sample has been delayed through an N-stage pipeline/filter that advances at M hertz.
Re:Open Source Needs FPGAs; FPGAs Need an On-Ramp
by pdelbarba on Friday March 31, 2017 @07:10PM
(#14009231)
Yea, I misspoke there. %s/speed/latency/
Certain industries (esp nuclear) really like them because they can "prove" the set of attainable states in the FPGA.
Re:Open Source Needs FPGAs; FPGAs Need an On-Ramp
by thesz on Friday March 31, 2017 @07:13PM
(#14009250)
Exactly.
There is an algorithm for detecting bursts of unusual activity which is extremely well suited for FPGAs: http://www.cs.nyu.edu/cs/faculty/shasha/papers/burst.d/burst...
Basically it is a tree of registers with checks. It can compute burst position and duration in the O(log(window size)) time (clocks). You look here at 2.5..5ns (200MHz..400MHz) multiplied by log2(window size) - 25..50 ns for window with 1024 samples. You just cannot get that kind of connectivity with CPU/GPU. Processing these samples in CPU will get you into several hundreds of ns, if not more.