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So Lets say I wish to analyse pixel streams ( uncompressed DVI)
I HAVE A 1 SECOND/16 000 000 time time window, until the next pixel. Multiple 24 bit parallel RGB combinations activate certain pins. I need maybe 256 different combinations, I guess cpld is out of the question ?? I need 128 different colors at least. So now I see FPGA, but I am worried, I need something with a good speed also 150 ns or less , on a 3.3v supply. What to do what to do ....Lien copié
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That sounds very much like a job for an FPGA and not a CPLD. I/O count may not be an issue but available logic and RAM resources almost certainly will be.
It all depends what you want to do in 150ns. That could represent A LOT of processing time. I think you're likely to run out of logic in a CPLD, even if you try and do very simple analysis. Plus, the lack of user RAM in the CPLDs means you won't be able to buffer anything like a frame of video which, I assume, is what you're going to want to analyse.- Marquer comme nouveau
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For video, use an FPGA - you get storage options with the inbuilt ram and extra stuff. Why the short time window?
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The FPGA's are going to require multiple supply rails, but is the correct device for the job.
I suggest you look at one of the many development boards as a first step. See if you can find one that gives you the io functionality you desire. It sounds like a mid-sized Cyclone III should be plenty for you needs. If you think the DE0 board will work for you, that's a nice cheap board to play with and get use to FPGA's. Of course there's all kinds available. They also have a whole range of Cyclone IV and Cyclone V boards available. www.terasic.com If you need a CPU in the system as well, the SoCkit is a great way to go as well. Pete- Marquer comme nouveau
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There will be no frame buffer, thats expensive...15$ per chip at least + a ram controller. I looked... big NO.
This MUST happen on the fly... AXH 175, what do you mean, is this timing reasonable or will the fpga actually be much faster than this ?? when the right color is there, 24 bit combination, turn on a pin. I must warn my ARM microcontroller, that does a simple task and gets ready for new pixel, wich could be the next one after. I need this on 3.3v also, if possible. or 3.3v tolerant I/O @ a minimum. Somebody plz provide me with a solution by altera.- Marquer comme nouveau
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so 150 ns is alot or little ??
No, no buffer, too much expense. Wouldnt be here if I ws gonna use buffer. I need something on 3.3 volt or 3.3v tolerant at least. Does altera make these or should I go lattice ?? What about the flex 6000 series, this too old ?? Those look 3.3 volt and pretty cheap. Cyclone 3 is so expensive @ 35$ on digikey.- Marquer comme nouveau
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The flex 6000 series is very old (about 15-20 years!) so you may struggle to find parts.
150ns is only 15 clocks at 100 Mhz (but your pixel clock will be slower than this). With different clocks, you'll need fifos to get across the clock domains, which is usually easier with a line buffer. Why cant you just buffer the video in the FPGA and then forward it out of the FPGA?- Marquer comme nouveau
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the smallest Cyclone IV E is cheaper than $35 at Digi-key. try EP4CE6E22C8N
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FPGA - definitely.
150ns - plenty. If you're looking to drive a pin high when a particular colour is present this will be more than enough time. All Cyclone parts are 3.3V tolerant and up to the job. They also come with FREE internal buffers for you to use.- Marquer comme nouveau
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So whats the difference between 32 bit wide 256 kbyte deep asynchronous ram from cypress that i was thinking of using as a frame buffer with an up counter and ram from the fpga , i didnt think of this, why does cypress notgo bankrupt, where does this solution come from, HEAVEN?
I am baffled.... Can you hold a complete frame, of lets say 1920x1200 pixel @ 24 bit color depth with a measly fpga... Nah, it cannot be...
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