03-22-2018 09:23 AM
the solution is to check the pin SFGBVS on the shematic on what voltage it is connected in my case was 3.3V:
Here the solution I got from Digilent support:
I am sorry for your issues.
Regarding the first one, in Nexys Video FPGA Board Reference Manual, USB UART Bridge (Serial Port) section is specified: “Signal names that imply direction are from the point of view of the DTE (Data Terminal Equipment), in this case the PC.”
Regarding the second one: That warning can be ignored and the board will not be damaged. There is a FPGA pin, called CFGBVS, that determines the I/O voltage support for bank 0 at all times, and for bank 14 and bank 15 during configuration. This pin connected to 3.3V on the board. You can check the Nexys Video schematics ( https://reference.digilentinc.com/_media/nexys-video:nexys_video_sch.pdf ) page 9. In addition to this configuration, you can specify in XDC file some constraints like CONFIG_VOLTAGE and CFGBVS. These constraints are used by DRC (Xilinx Design Rule Checking) to validate your design when the bitstream is generated. You can read more about DRC here: https://www.xilinx.com/itp/xilinx10/isehelp/pfp_p_drc.htm. This is a good practice but not a needed one.
If you want to solve that warning you can add the following lines in your XDC file:
set_property CONFIG_VOLTAGE 3.3 [current_design]
set_property CFGBVS VCCO [current_design]
or you can use the Nexys Video XDC from Digilent GitHub account ( https://github.com/Digilent/digilent-xdc/blob/master/Nexys-Video-Master.xdc ). I updated this file with the CONFIG_VOLTAGE and CFGBVF settings.
the Warning was:
CFGBVS-1 CFGBVS #1 Neither the CFGBVS nor CONFIG_VOLTAGE voltage property is set in the current_design. Configuration bank voltage select (CFGBVS) must be set to VCCO or GND, and CONFIG_VOLTAGE must be set to the correct configuration voltage, in order to determine the I/O voltage support for the pins in bank 0. It is suggested to specify these either using the 'Edit Device Properties' function in the GUI or directly in the XDC file using the following syntax: set_property CFGBVS value1 [current_design] #where value1 is either VCCO or GND set_property CONFIG_VOLTAGE value2 [current_design] #where value2 is the voltage provided to configuration bank 0 Refer to the device configuration user guide for more information.