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I'm working through Mike's excellent book and am on the 1 bit (Delta Sigma) DAC chapter 16. I've also taken some time to peruse the Xilinx App Note 154 that is referenced in the chapter. In para 16.4 of the book, the VHDL 'code' in para 16.4 library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; entity dac8 is Port ( Clk : in STD_LOGIC; Data : in STD_LOGIC_VECTOR (7 downto 0); PulseStream : out STD_LOGIC); end dac8; architecture Behavioral of dac8 is signal sum : STD_LOGIC_VECTOR (8 downto 0); begin PulseStream <= sum(8); process (clk, sum) begin if rising_edge(Clk) then sum <= ("0" & sum(7 downto 0)) + ("0" &data); end if; end process; end Behavioral; The meat of the work is done here: sum <= ("0" & sum(7 downto 0)) + ("0" &data); This makes sense and works quite nicely on my DUO/Logicstart. I tested this using switches for the Data input and output the Pulsestream to an LED. My confusion concerns how this is implementing the Delta Adder in the App Note (which is actually a merge as explained in the App Note). I've managed to pretty much wrap my head around the App Note theory, but cannot understand why the copies of the MSB are not prepended to the sum(7 downto 0) element. Thanks, -Chris
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Sorry to bring a very old thread back to life but this looks like just what I need. I'm working on another 70s Atari arcade game called Subs and need a SVF filter for the sonar ping sound circuits, this is the only part I have not yet completed. I'm a novice when it comes to DSP techniques and until this came up I was actually not familiar with the concept of the SVF filter at all, it's an interesting concept though. Anyway what I need is a pair of filters (two separate input and output channels) bandpass with a 1kHz center frequency. The source is a decaying envelope of white noise from a LFSR which I can make any width necessary. Could somebody give me a few pointers on integrating the filter out of this project into my own and setting up the parameters? I will of course share the code for my project when I'm finished.
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A non compressed bitstream has always the same size which directly relates to the type of fpga. For a spartan-6 lx9 it is around 330KByte (when I remember it right, I‘m currently traveling so I cannot check). But it is possible to attach additional data to the bitstream e.g. with a program like bitmerge http://hamsterworks.co.nz/mediawiki/index.php/Config_flash or the -a option of papilio-prog This additional data can than be read with a spi flash interface added to the fpga design. I‘m not sure if papilio-prog erase always sectors (64KB) or pages (4KB). The flash chip on the Papilio Pro supports both. Anyway, when I use the flash in the Papilio Pro for own data I always start at 512KB, this is on the save side.
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See page 77 in this document: https://www.xilinx.com/support/documentation/user_guides/ug380.pdf The flash chip is erased in units (aka sectors) of 64kB so programming a 65kB bitfile will erase a 128kB area. Magnus
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Thank you for the info, Thomas Hornschuh. It was as I hoped. But what do you mean by "Normally"? Are there cases when the entire flash is erased? Anybody who knows or has an idea about the "worst-case" size of a SPARTAN6-LX9 bitstream? I.e. the size of the bitstream for the largest possible SPARTAN6-LX9 application.
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Normally it just erases the number of blocks the new bitstream occupies.
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I want to buy skullcandy method wireless earphones but i am worried about that is it good earphones for running or sports earphones?
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Programming the flash of Papilio PRO with a new FPGA application will require erasing the flash or a part of it. My question is: How much will be erased? The entire flash or only so many blocks that the application will occupy? Or "something in between", e.g. "always 2 MBits"? Or the number of blocks occupied ny the greatest possible application for SPARTAN6, by assumption different for ...LX4 and ...LX9?
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If you can, look into loading the WebPack that installs under native Windows rather than VirtualBox. Integration with DesignLab actually works, much less hassle. If you do, be sure to go through the steps to fix the DLLs.
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Thanks Chris, It's definitely a possibility here as they are using virtual box, I will look into that.
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Is gadget factory moving sites or shutting down?
Chris Wilcox replied to Mikkel Jeppesen's topic in DesignLab IDE
Glad things are back! I just picked up a DUO (2M) and a LogicStart from Seeed and I was afraid I had been orphaned just after my purchase arrived. I was able to find the answer to my worry that the upper 5 LEDs on the LogicStart did not have limiting resistors (they are on the DUO) earlier today on the forums Working through the Introducing the Spartan 3E FPGA and VHDL pdf, my first foray into FPGA - enjoying the boards thus far. -
If ISE is running in VirtualBox, deselect the DUO in Devices->USB from the VirtualBox Menu. I ran into this when trying to load a bitfile from the Papilio Loader running under Windows 10.
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Hello, One of my students has an issue where the DUO is not being recognized at all on her windows 10 machine (nothing shows up in device manager). She has installed papilio loader 2.8 twice, rebooted and even installed the FTDI drivers (which I believe she did not need to do) and still nothing. Any ideas? Thanks
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Hi, Over the last couple of months I have been working on a module to communicate over the can bus. I have been using the papilio pro board as main development platform for that purpose. As a result I created a wishbone interface and some code running on the zpuino to be able to interface with the can bus. Using DesignLab was a very nice way to get started. thank you for that. the project can be found here https://github.com/keesj/can-hdl and documentation here https://keesj.github.io/can-hdl/index.html
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Is gadget factory moving sites or shutting down?
keesj replied to Mikkel Jeppesen's topic in DesignLab IDE
Hello, Good to know. there are some other pages that currently down (see other topic) -
I see most printed circuit boards are green in color. I’ve seen some blue and yellow boards, but not so many – so I have a question: Why are most PCBs green? The above question is not only asked by electronics hobbyists but also questioned by engineers, so today let’s unravel the mystery. http://www.pcbindex.com/ What the green part of a circuit board is A ‘green’ printed circuit board is not actually green all the way through. The only green part is the outer covering of resin called the solder mask or solder resist/oil. This is a hardened resin with colored pigments that is applied to the boards in a silkscreen fashion. The purpose of solder mask is to protect the electronic traces underneath from moisture and dust and to control the flow of molten solder. The actual core of a typical Fr-4 circuit board is a plain, dull, yellow color, but the solder mask can come in many colors such as blue, red, yellow, black and white. Even more exotic colors can be found for the extravagant such as orange, pink, purple, matte versions and even mixed color boards. So, the question remains, why green? Top Reasons Why Most PCBs are Green in Color 1. Green can relieve visual fatigue and aid in inspections In the early days, due to technological restrictions, quality inspections relied on workers manually checking the boards with their bare eyes. Squinting at tiny circuits all days is tiring work, but neurologists and psychologists agree that the wavelength of green light has relaxing effects on the body and can reduce fatigue. Additionally, they have found that the sensors in human eyes, or cones, are most sensitive to green light. Therefore, the contrast is greater between the circuit traces, pads, silkscreen printing and empty spaces. Just by observing the boards from the outside, one can easily identify defects in the outer layers. Compare the below images of green boards to other colors such as blue, yellow or even black and white. With higher contrast, errors are easier to spot. Black: Tilt me and you can see the circuit traces in the light. White: Traces..? What traces? Of course, nowadays PCB manufacturers use flying probe techniques and Automatic Optical Inspection (AOI) for these tasks, which is very effective in spotting errors. But there is another very important technical reason why most PCBs are green. 2. Green solder mask is physically superior Due to the traditional aspect of using green pigments, R&D into making better solder mask oils focused on the standard green color. The actual chemical pigments used influence the performance of the resin during application and in the field. When demand is pushing form factors to their limits, no one cares about having pink boards. As a result, green solder mask now has superior properties compared to other aesthetically orientated colors. Most prominently, commercial green solder mask is the only available color that can reliably produce solder mask dams of 0.1mm (4mil). Next up is red, yellow and blue that can produce 0.12mm dams and then black and white which can only achieve 0.15mm. Solder mask dams are vital for ICs and fine pitch components since they are valuable in preventing solder bridges from forming. Solder mask is typically applied using silkscreen techniques. A large blob of oil is dragged across a screen mesh with the circuit board underneath. The circuit board is removed for curing, and the next board goes under the mesh. But hey, hold on, I want another solder mask color. Well, then you have to remove the excess solder mask oil and wash the silkscreen before applying the new color. Otherwise, a silkscreen station is needed for each color. Furthermore, for white or lighter solder mask shades, you’ll also need another station for the black silkscreen ink. Then, if you find that one color is not particularly popular, the chemicals will be wasted and efficiency will be impaired. Similarly, some factories will not accept certain combinations of PCB features with colors other than green, since green is by default the most popular color. Consider this: typically, in a PCB fab house, many designs from various orders are grouped together on one panel (panelized). This way, they can make the most out of PCB real estate and reduce waste. But there are many processes that require the entire panel to be processed the same, like surface finishes and plating for castellated holes. So all boards on a particular panel must have the same requirements. By adding more and more specific features, the factory is more likely to end up with insufficient designs to fill a panel at one time. Adding factors such as solder mask color or board thickness into the picture multiplies the number of possible combinations, and multiples the waste and therefore cost. If available, you may end up paying for the cost of the entire panel. So by restricting certain combinations of colors and features, factories can keep costs down. Not to mention, developing a new solder mask oil that performs well as an electrical insulator, applies and adheres evenly, cures well and looks visually appealing is not a simple process. As such, expect to pay a premium for special requests like matte beige. So there are many reasons to love and not to love green. Which do you like best and why? Join our ongoing poll to pick your favorite below. Seeed Fusion’s PCB fabrication service offers a good range of solder mask colors to suit your prototyping palette from deep-sea blue, Ferrari red, sunshine yellow, slick black, pure white and of course good ol’ green and at no extra cost.
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Hi there. The tutorial that ought to be here seems to have disappeared: http://papilio.cc/index.php?n=Papilio.HighSpeedUART
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And I got iRobot Roomba. I have read a lot of articles on https://best4yourhome.com/irobot-roomba-comparison/ and decided to buy it. I am fully satisfied.
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Loading Papilio Bram only project on papilio pro
hroyster replied to hroyster's topic in Papilio Pro
As a follow up, I noticed that the ucf callout for the usb_tx and usb_rx seemed to be reversed from the pro ucf so I switched them (not sure about why this worked). When I did, the arduino programmer did not error on the missing core but generated the following error which looks like it found the core but did not see what it wanted to see. error - Board: Unknown board @ 96000000 Hz (0xb4010f00) Cannot program flash on non-sector boundaries! I thought the Bram flash ( i assume this is the program space in the bram flash) would be placed in the same place in the core but maybe not - there must be some ID issue. I have attached the project if any one has a chance to take a quick look. Thanks again for any help. Howard Flash_SD_2.7z -
I have built a special papilio that is a clone of the papilio pro. It also has spansion flash chip that shares the address and data lines with the SD memory. I want to create a bram only zupino core that I load into the pro like board. This will free the address and data lines of the SDRAM. If I de select the SDRAM on the new board and select the spansion flash, I can then use i/o registers to transfer files from the SD card on the CL wing to the spansion flash. Then I will load the actual xilinx program that uses the flash directly with no papilio core. Is there a straight forward way to do this? My first attempt was to modify the papilio 500 project with SD cl wing and modify the ucf file to correctly connect to the pro Hardware. The xilinx loaded and verified, but the arduino load operation could not find the bram core?? error (Cannot get programmer version, aborting) I figured someone else may have tried this obvious modification of loading the smaller zupino bram only core on the pro board, but I couldn't find a reference in the forum search. Thanks in advance for any help. Howard Royster
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Is gadget factory moving sites or shutting down?
Jack Gassett replied to Mikkel Jeppesen's topic in DesignLab IDE
Hey guys, I'm very sorry for the hassle, I'm not shutting GF down or moving websites. I started a new job and went through a very intensive two week training period with 14 hour days so there was no time left to look at forum posts here. The hosting for the downloads just happened to expire during that period and I didn't see the emails. I saw it once the training was over and everything should be sorted out now. Things should calm down going forward and I should settle into a routine where I can keep up with forum posts going forward. Once again, sorry for the hassle. Thanks, Jack. -
Program the ATmega32U4 without boot loader via USB
Jack Gassett replied to Pooyan's topic in Papilio DUO
Hey Paul, glad you got is sorted out. Sorry for the slow response. Jack. -
Hello Sandro, The only thing that is different between the 2MB and 512KB boards should be that in the 2MB board there is one extra address line that the 2MB chip provides. The circuit board is exactly the same, its just that on the 512KB board that address line connects to a pin that does nothing while on the 2MB board it gives access to more address space. Jack.
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Is gadget factory moving sites or shutting down?
keesj replied to Mikkel Jeppesen's topic in DesignLab IDE
Hi, I do not know what is going on. I can also not download the IDE.
