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Verify UART is/isn't working on project

Former Member

Thank you in advance for any help anyone has to offer. I'm new to software/virtual hardware and coding. I'm currently working on a project of adding UART functionality to an FPGA image. I have created, instantiated in top file, and added ports necessary for our utility to build the FPGA image and now I'm not sure how to verify the UARTS are/aren't working or not. The image builds fine (no errors) now after some debugging. The UART I'm using is a 16550 on a Zync 7030 I believe. How do I verify these are working correctly? Again I'm new to all this and yes still learning all the commands/tools to interface with the board this is on. Thanks again for any help.

  • 0

    Are you using PlanAhead/ISE or Vivado Xilinx tools? Is this a custom board or an off the shelf board?

     

    Are you using one of the Zynq PS (Processing System) UARTs or is the UART you have implemented one of the AXI UARTs from the standard library or did you implement you own UART? If so, what is the internal interface.

     

    Is the external UART interface RS232 or just logic levels and what is the physical connection (connector?).

     

    Are you using an Operating System or is this a 'bare metal' application?

     

    -Gary

  • 0 in reply to Former Member

    -Vivado Xilinx tools; custom board

    -I'm using an AXI Uart from the standard library. I used xilinx to build the instantiation module and coregen to create the .ngc file.

    -I believe it is rs232 and AXI

    -OS. This is being done in linux

  • 0 in reply to Former Member

    Once you have built your hardware design, including constraints to direct which physical pins the UART signals are connected to, you should be able to export your design to SDK. Once there you can start with a simple hello world example if you have connected UART 1 of the Zynq PS as a console connection similar to the way it is done in the MicroZed tutorials 01 and 02 located here:

     

    http://www.zedboard.com/design/1519/10

     

    Once you get that working you can use the auto generated test application, as is shown in the MicroZed tutorial 03, to test your AXI uart. You can also take a look at the AXI UART example code by opening up the .mss file in the SDK and, next to the AXI UART, click on the 'examples' link. You will need to connect a terminal program such as Tera Term or Putty to the rx and tx from your UART via a serial port or USB to Serial adapter.

     

    -Gary

  • 0 in reply to Former Member

    I think I understand what you are saying. However, we build the design into an mcs file that we then use the SDK to program the fpga on the board with the new mcs file. I'm assuming that once this is done, I could attempt what you are suggesting, am I following? see if serial communication works between my terminal window and the board?

  • 0 in reply to Former Member

    Most users use the SDK to generate the .mcs file and program it into the QSPI Flash. It is usually easier to initialize the Zynq PS and load the bitstream via JTAG, using the SDK, initially to verify and debug both the hardware and software.

     

    To build the .mcs file in the first place you will need to use the SDK to generate an FSBL (First Stage Boot Loader) and, along with the ps7_init.h and ps7_init.c (exported to the SDK from Vivado), the FPGA bitstream and your software application.

     

    It would probably be helpful to go through the MicroZed tutorials I referenced earlier, or the Zynq Concepts, Tools and Techniques tutorial for the Zedboard or for the Xilinx ZC702 evaluation board to understand the development and debug flow. Avnet has a hands on full day class for developing Zynq software and another for developing Zynq hardware if you are able to attend one in person. Otherwise we will be posting the material on the zedboard.org site in the near future.

     

    -Gary