jbb

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Everything posted by jbb

  1. jbb

    Papilio DUO Kickstarter - Feedback request!

    Yeah the problem isn't duties and VAT, it's the fact that the delivery (well I object to those too, but that's a different issue). The issue is the additional fee that the delivery companies charge for collecting that from me. I'm sure I have no legal requirement to pay them for a "service" I never requested from them but it's not always that easy. it's not a problem though, I'll complain and pay it if I have to Anyway kickstarter is looking good I wanted an HDMI port and I'm not sure it will reach the goal for that, but I guess it's not that hard to make a board myself if I have to
  2. jbb

    Source control / ISE

    Excellent, thank you.
  3. Using the xilinx ISE package with VHDL, but want to store my code in git. There are many, many files in the directory, does anyone know which I need to store in order to have a working system? Obviously my .vhd and .ucf files, and .xise appears to be a project file? Are there any others I need to save? And what about generated IP components? It's not clear what i need to store for those. Anyone got any ideas or experience of this?
  4. jbb

    Timing constraints

    Thank you for that. Ah, I wasn't aware that the DCM component was clever enough to pass through the timing, that makes sense though. Thank you for the advice on the pack I/O properly. It seems it was already turned on so I assume it's the default, but defintatly worth checking!
  5. jbb

    Timing constraints

    I'm slowly working on my own (slow and basic) sdram controller while learning VHDL (I only did verilog before). I'm using a DCM block to generate a 100Mhz clock for my state model for this. It worries me that I might try to do too much logic and signals won't be computed in time before the next clock comes along which obviously will break things. I assume this is what the timing constraints are for though? To verify that your design will work at the speed of the clock. But I can't find any information about how to add constraints saying that a specific signal is generated using the 100Mhz clock rather than the 32MHz standard clock for example so the logic needs to be fast enough to work for that. Or rather I can find lots of information. Too much... And I don't know where to start. Can anyone either help me out with how to set up suitable constrains, or point me at an introduction to how to do this rather than the hundreds of pages of documents that tell you everything at once. (Which obviously I'll read once I understand the basics)
  6. jbb

    UCF Files

    When I use the generic .UCF file with all the pins defined in, my compilation fails because I'm not using anything connected to most of the pins. Is there any way to tell the compiler to ignore that or do I have to comment out the unused lines from the UCF file?
  7. jbb

    Got mine

    Ah the memory is 16 bits wide, I was assuming a byte, that will double the bandwidth and make it perfectly usable
  8. jbb

    Got mine

    Mine just arrived in the post this morning, excited to see what I can do with it. It took 13 days from ordering it at seeed to delivery in the UK which was far faster than I'd expected. I would like to use it to generate some graphics, I think my first project will of course be to flash some LEDs to make sure everything works, then I want to get VGA output working. I'll want to get the RAM working for that too. I've done VGA on other devices so I'm confident I can make that work but RAM is new to me, so that should be fun. I'm more interested in verilog than embedded CPUs although I might try that out too I'd like to make it generate HDMI after reading other posts eventually. Am I right to understand that it can be directly connected to an HDMI lead, subject obviously to correct configuration and design? The signal levels etc are correct for it? Going to be a while before I'm up to doing that anyway. Thanks for this anyway, gives me something fun to play with and learn over christmas
  9. jbb

    Got mine

    First of all Merry Christmas to everyone here Secondly I've been looking into using the sdram for video. I have a question though. With a fairly low video resolution of 640x480 there is a pixel clock of 25MHz or so. If I need 3 bytes per pixel for RGB then that's 75MB per second needed. But looking at the memory it can only return one every 10ns but that's if you manage to read a byte every clock cycle at 100MHZ which isn't really possible and if you manage one every 2 clocks then it's only 50MB/s which isn't enough even for this lowish resolution. Am I missing something?
  10. jbb

    Got mine

    Thank you. It's a great device and although it's a challenge to learn new things with it, it's a lot of fun!
  11. jbb

    Got mine

    Well I got a simple VGA 1 bit per color adapter working, next step is I want to get it to display from SDRAM rather than just low resolution block memory. I'm thinking first I should get it working with block memory with artificially introduced latency as I'll have a few clock cycles latency on any SDRAM controller, does that make sense. My real next question is about SDRAM memory controllers. Do we have anything we can just drop in? I looked at the hamsterworks posts which were very helpful but not quite a drop in component. I can work on my own, it's a little out of my comfort zone as I'm a c++ developer and new to this, but I figure it's not beyond me to make one. Am I right in thinking that you need to ensure you do refresh cycles frequently enough but apart from that the speed isn;t that important as I think it would be nice to start slow so I can look at outputs on my oscilloscope if necessary...
  12. jbb

    Loading the SPI Flash on the Papilio Pro

    Is there any source code for any of this, or any information on how the loader works? Mostly I'm just interested for it's own sake so nothing urgent
  13. jbb

    Writing a USB 1.0 stack.

    Sounds good! Is it possible for FPGAs to self-program in some way? Just wondering if it would be possible to use this to program an fpga so it didn't need an external microcontroller or usb chip or JTAG programmer... I guess it would be possible to use it to program SPI flash containing a fpga program at least.
  14. jbb

    Trouble programming pro

    I've not managed to sucessfully program anything into my papilio pro. I'm using the loader program I downloaded from this site. The target board drop down only has "BUtterFly One" and various "PapilioOne ..." opions for 200k and 500k and does not mention Papilio pro. If I select auto detect then then I get "JTAG chainpos: 0 Device IDCODE = 0x24001093 Desc: XC6SLX9" and it appears to work however the boards doesn't seem to do anything. SHould the loader have an option for papilio pro or do I have the wrong version? I tried the SPI option as well and that took about 1 full minute to work but gave no error - but does not appear to have programmed my code to the device properly as it doesn't work. I believe my code to be correct as I have no problems with other fpga boards but of course it could be wrong. Is the original programming file that flashes the LED available anywhere to try putting back as this appeared to work when I first powered up the board, so I can eliminate my code as the cause of this not working? Or do you have any suggestions for what I might be doing wrong? Thanks...
  15. jbb

    Trouble programming pro

    I agree, I think the USB change thing was incorrect and just a coincidence. It seems to work but unreliably as you say. It seems to work reliably for several attempts and then fail several times in a row then work again. It's usable anyway now I know this I just try until it works.
  16. jbb

    Trouble programming pro

    Ok never mind, I changed USB ports on my computer and now it appears to be working as expected. I'm not sure why one USB port would work and another would "appear" to work but not actually work, but I can confirum that the device appears to be working properly and sorry for the long unnecesary question.
  17. jbb

    Got mine

    Thank you for the information. It's going to be a while before I feel ready to tackle HDMI but it's good to have some reading. SO much to learn
  18. jbb

    Papilio Pro User Guide!

    Perhaps I'm doing it wrong or missing something but the link to the user constraints file on this page http://retrocade.gadgetfactory.net/index.php?n=Main.PapilioPro at the end of the page doesn't seem to link to the file.
  19. jbb

    Papilio Pro User Guide!

    I've ordered myself one of these... Slightly concerned though about the comments about the SDRAM. My understanding is that it's not too difficult to use with your own controller, as long as you're not looking to get every last bit of speed out of it, is that correct?
  20. jbb

    New SDRAM board?

    Is this the board that is mentioned on the kickstarter than now has sdram instead? Just got a couple of questions and wanted to make sure I was in the right place.
  21. jbb

    New SDRAM board?

    Thank you for that answer, it was what I was hoping for. Ok, making a controller for sdram looks tricky but easy enough for me to understand it. It's not as complicated as I thought. And as your sample is in VHDL it gives me the excuse to learn it I've been looking for. (Only really used verilog until now).
  22. jbb

    New SDRAM board?

    Ok mostly I'm interested in this for the synth thing, but also to have a nice new fpga to play with! Well I asked this on the kickstarter pages but I'll ask here in case anyone has any more information. I don't expect a quick or easy answer, just any information that anyone has at some point in a more appropriate place than a kickstarter page update. How easy will it be to access the sdram? I realise that using the memory isn't trivial even with a controller, but while I might have been able to control SRAM it's a bit harder to control sdram. My other question is, is it possible to use the usb port to send data to the fpga or is it only good for programming it? I see there is a schematic but it looks like eagle and I don't have that installed at the moment so thought I'd ask. Anyway, it looks like an interesting board, just what I need which is why I backed the kickstart project for the synth and this