• Content Count

  • Joined

  • Last visited

About Squirrel

  • Rank

Recent Profile Visitors

1895 profile views
  1. I am not so sure about the hamster thing, but I am sure about the following: The FreeRTOS handler for the AXI register write occurs at nearly exactly 48KHz (validated with an oscilloscope). Sometimes maybe +/- 100Hz under heavy loading, which was not the case in my baseline testing of the AXI_I2S_ADI If I pre-fill the buffer every frame until it is full as a defensive measure, things get even worse; I see the left and right channels swapping rapidly for maybe 50 or so samples. I don't have a trace handy to verify the exact behavior I have never had luck getting reasonable audio out with 32-bi
  2. sbobrowicz, I would like to pick your brain a little on the I2S adapter if you don't mind since you have been working with it recently. I am running FreeRTOS with an audio task running at 48KHz. I am also running the codec in 48KHz mode. I realize that every frame of the audio output task, I am not guaranteed that the FIFO will be empty enough to write both the left and right samples. However, if I keep track of which I wrote every frame, I would expect that the I2S adapter would do the same: u8 writeToCodecInterface(u32 data0, u32 data1) { u8 writeMask = 0x00; // From the VHDL: // I
  3. The devicetree DTS file is as follows, obtained using the Git master-next branch of the Linux-Digilent-Dev repo: /* * Device Tree for Zybo board * Partially generated by Device Tree Generator 1.1 * * (C) Copyright 2007-2013 Xilinx, Inc. * (C) Copyright 2007-2013 Michal Simek * (C) Copyright 2007-2012 PetaLogix Qld Pty Ltd * (C) Copyright 2014 Digilent, Inc. * * Michal SIMEK <[email protected]> * Tinghui Wang <[email protected]> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License a
  4. I was wondering if anyone could guide me in the right direction for troubleshooting a USB peripheral connection with the Zybo board running embedded Digilent Linux. My boot is as follows, which shows the USB root device (not OTG - the title is a mistake) appears to be loaded properly but no USB devices show: U-Boot 2014.01-00005-gc29bed9 (Feb 01 2015 - 22:39:09) I2C: ready Memory: ECC disabled DRAM: 512 MiB MMC: zynq_sdhci: 0 SF: Detected S25FL128S_64K with page size 256 Bytes, erase size 64 KiB, total 16 MiB *** Warning - bad CRC, using default environment In: serial Out: se
  5. Squirrel

    ZYBO Board w/ XADC

    This has gotten me significantly farther, thank you for the reply! For anyone who browses this topic later: The XAdcPs_RawToVoltage conversion macro is 3.0 V based and not 1.0 V; create your own for the AUX channels (unless anyone knows of one already there?)
  6. You can also use the one provided by Analog Devices (here, go into library and find the AXI_I2S_ADI), which comes with the Zybo reference design. I get negative slack warnings in Vivado 2014.4 with this, but I have not seen terrible results with it. I have, however, seen some weirdness with the input range into the AXI_I2S_ADI IP from the PS side. EDIT: I may start a post on the negative slack and range issues at some point, but for not I'll leave it as "use at your own risk"
  7. Squirrel

    ZYBO Board w/ XADC

    I was wondering if anyone had experience with the ZYBO board getting the XADC interface to work properly. I have the following diagram in Vivado 2014.4: <Vivado2014_4_Diagram.JPG> The associated XADC wizard settings are as follows: <XADC_Wizard1.JPG> <XADC_Wizard2.JPG> This lets me get the temperature from the XADC, but I am getting 'weird' values for XADC pairs 0-3 (which are hardwired to the XADC PMOD connector on the ZYBO); there doesn't appear to be a dependence on temperature though... here is AUX0, for example: <TempVsAUX0.JPG> In relation to VpVn (V
  8. cfatu, the project and associated bitstream (Work.bit) worked fine for LD3, I'm not sure if I should now suspect an issue with the Vivado / Xilinx constant block? Interesting result regardless... I'll stick to VHDL. In re: to the SD card, it looks like I had a 'bad' FAT32 partition alongside the ext4... after a reformat, everything looks good. This can be marked as solved, thank you for the support!
  9. I’m not entirely sure where to put this RMA, but I think the ZYBO board I just received may have a faulty LED (LD3) and a faulty microSD card from the accessories kit. One thing at a time… first, the LED. I have been having trouble getting u-boot (and subsequently the Digilent Linux distro) to work on the board. In order to make sure that at least the PL portion was being programmed correctly, I made a basic project in Vivado 2014.1 for the xc7z010clg400-1 SoC target. The LEDs are hooked to a constant IP block [3:0] with a constant value “1111”: But the ZYBO response does not have a