Gra

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  1. Gra

    CMOD A735T High Current Consumption

    Hi MTlabhishek, I took a really quick look at the schematic, looks like the max power out on that converter is a little under 5W, so you shouldn't be seeing 2 amps in at 5V. I'd start by re-loading a reference design and measure the current again. Your design can change the power drawn, design errors can also cause large currents to flow. Gra
  2. Gra

    Stupid Q: What does a loop in a HDL really mean?

    Piasa, it was actually an example to show a loop, not to demonstrate the best way to describe a shift register. Gra
  3. Gra

    Stupid Q: What does a loop in a HDL really mean?

    its just a way of reducing the amount of HDL you have to type Here is an example, say you want to describe a shift register, you have an input and an output data pin, say input_port : std_logic; output_port : std_logic; you are going to need some flipflops for your shift register, lets have 8, you need an input to each flipflop and an output from each flipflop, here are some sigs for that input_signal : std_logic_vector(7 downto 0); output_signal : std_logic_vector(7 downto 0); then you need to describe the flipflops, Process (....) begin if (clk ‘event and clk = ‘1’) then output_signal <= input_signal; end if; end process; Now you have 8 individual flipflops with inputs... input_signal(0) input_signal(1) input_signal(2) input_signal(3) input_signal(4) input_signal(5) input_signal(6) input_signal(7) and outputs.... output_signal(0) output_signal(1) output_signal(2) output_signal(3) output_signal(4) output_signal(5) output_signal(6) output_signal(7) So to get your shift register you will need to connect the output of the first flipfloip to the input of the second flipflop and so on.... Then connect your i/o ports, so something like this input_signal(0) <= input_port input_signal(1) <=output_signal(0) input_signal(2) <=output_signal(1) input_signal(3) <=output_signal(2) input_signal(4) <=output_signal(3) input_signal(5) <=output_signal(4) input_signal(6) <=output_signal(5) input_signal(7) <=output_signal(6) output_port <= output_signal(7) All a loop does is compress the notation, the above would do something like this... i = 1 to 7 input_signal(0) <= input_port input_signal(i) <=output_signal(i-1) output_port <= output_signal(7) Useful notation if the shift register was much bigger, or you wanted to change the size easily, also useful in big repetitive circuits like hand crafted filters. Not helpful when you are working in teams and they are used for something as simple as the above, as you can see its easier to read the long-hand description than a loop.. Hope that helps... Gra
  4. Hi Jamie Just to add... A recent design job I did had most of the components that you mentioned. It landed on a 20nm Kintex Ultrascale. Gra
  5. Hi Jamie, I would initially put a “bare bones” type of design together with no physical hardware, get the PCIe blocks and transceivers into the design, stick some filters, clocking etc in there and built it. If you are buying off the shelf hardware rather than building your own, you can look at the various options on the market... Get the physical constraints file and device types for those options then stick that into the mix and go for timing closure (which is often the most challenging step on designs like the one your describing). Simulate, refine close the timing. Once you are happy, buy the right hardware and start the debug process with integrated logic analysers etc. In your position I’d hire an experienced FPGA engineer, it will save you time and money. Gra
  6. Gra

    Spartan 3 Starter Board Help

    Hi Nick, You use ISE to develop, as part of ISE suite you get a tool called impact, I think the Spartan 3 was supported right up to ISE 14xx (check before you download). You can configure the FPGA with a bit file or configure the platform flash with something like an mcs file, bit file is volatile, the mcs will configure the fpag at start up. When you plug it in you should see both devices on your jtag chain (in impact) you click on the device and prog it. loads of info here https://reference.digilentinc.com/spartan-3:spartan-3 Note on a more modern Digilent board you don't need to buy a jtag cable Gra
  7. Gra

    FPGA file types

    Thanks guys... and D@n the article was very useful, thanks. Gra
  8. Gra

    FPGA file types

    I’m a little bit stuck, can anyone help me with this. In a project I’m looking at there are 3 file types, mcs bit and fw .bit files (fpga config volatile) .mcs goes on the non volatile device, used to configure the FPGA at startup .fw file .... I don’t know, if I had to guess I’d say, maybe the software instructions for an embedded processor, but that's just a guess. Can anyone tell me just what the .fw file does? Many Thanks
  9. Hello HallmanLabs, Your line splitter looks quite bulky, is the current clamp completely closed? Gra
  10. Gra

    spartan 3e starter kit win 10

    Hi John and Mikel, I had an identical problem a few years ago, turned out that if you plugged the cable into the PC before you installed ISE (or Webpack) it did something strange with the cable driver. I had to uninstall ISE, re-boot the PC and start again (with the cable unplugged).. That did the trick. I may also have had to remove a random driver that windows installed for the cable before I re-installed ISE too. Definitely wasn't on Widows 10 (possibly XP, maybe 7). Did you plug the cable in before installing the software? Anyhow, as I said it wasn’t on Win10 but I thought your problem sounded so similar that it was worth mentioning this. Gra
  11. Hello Bianca, Thanks for the distributer list, its a pity that RS Components aren't a Digilent distributer, also it didn't occur to me to go to Blackbox in Oz. I think of Blackbox as the place to go for Xilinx training, but as you pointed out they are a Digilent distributer, so I'll contact those guys next time I need a dev board. Anyhow its great that we can now buy some Diligent boards locally, and a bigger range of electronic components too. Kind Regards Gra
  12. Having recently listened to the podcast by Digilent’s founder, and hearing about how the company started, and that Dev boards are bought by students using their Pizza and Beer budget, I thought the following may be good news. Here in NZ life is pretty sweet, but because we are a long way from, well from everyone really... buying things from places like the USA can end up more expensive than you’d imagine. Here is an example, when I bought an Arty board it cost $99, granted that’s not a lot of money for this great little piece of kit.. but the postal cost to get it here was an additional $70. There should also be 15% sales tax added at the NZ border, but on low value items the nice guys at NZ customs often just let you off with the bill. There is some good news... RS Components have opened a branch right here in NZ, and they sell Digilent stuff. They don't have heaps of Digilent stuff at the moment.. But I can see 10 Digilent dev boards on their website. The fact is, I can now buy a Digilent PMod board for less than the cost of the USA postage alone. The next thing that caught my eye is the local postage.. On the RS website it says FREE NZ delivery for all online orders. This is really, really unusual here in NZ, in fact I cant think of another company that does this. I usually pay $20 to $40 for postage on electronic components. Hope that's useful... Enjoy the saved Pizza money. Gra It would be great to see more Digilent stuff available from RS Components..
  13. Gra

    Is there an arty drawing available?

    Great, Many Thanks Bianca. Kind Regards Gra
  14. Gra

    Is there an arty drawing available?

    Hello, Does anyone know if there is an outline drawing of the Arty board available, one that gives the Arduino/ChipKIT Shield Connector positions? Many Thanks Gra