07-23-2017 05:34 AM
Hello! When using XADC + Xillybus, I open Hardware Manager in Vivado just to monitor the XADC. Temperature is always -273.1ºC and volts in VAUX0, VAUX8 and VP/VN is always 0.00. When I run this tutorial I use the Hardware Manager again to monitor and everything seems fine, temperature is at 30ºC and volts in VAUX0 looks great (even change when I put my finger on the pins, as expected). So I am starting there must be something wrong with the combo XADC + Xillybus or maybe I'm not accesing the XADC properly? Although the XADC seems to convert, but it looks like it's always converting the same thing (although values change a little, implying is not stuck in the same result forever) and I'm always getting values like 0080, 0081, 007F and so.
Do you have any clue on what might be causing this? I'm currently connecting the EOC signal of the XADC to the DEN of the XADC to output values and the CHANNEL signal to the DADDR ("00" & CHANNEL, since CHANNEL is only 5 bits and DADDR is 7 bits wide) as proposed in the XADC doc.
Do you have any clue on what might be causing this? thanks!
07-23-2017 11:03 AM
@pedro4 Well -273.1C is zero Kelvin. So pretty much everything is zero.
I would add some ILAs and check the bus
It seems to me too many moving parts at this point
07-23-2017 12:29 PM
@hbucher I tried doing what you mentioned, and I probed EOC, DRDY and CHANNEL[4:0] from XADC and:
None of them triggered tho, but I think that might be cause I don't know hot to use ILA properly, never used it before.
But I tried printing which channel the XADC was converting and it's always channel 9 (that is ADC A offset). I don't really understand what's going on.
07-24-2017 09:02 AM
Sorry for the double post, but I can't see an "Edit" button anywhere.
So I've been doing some tests. I started a new fresh project where I only instantiated an XADC (I used the wizard and set it up exactly as the one I have set up in my Xillybus project). Left all the outputs open and just fed it with a 100 MHz clock. Generated the bitstream, programmed the FPGA and using the Hardware manager in Vivado, I monitored the XADC and it worked perfectly! Then I just copied it to my Xillybus project and I created an VHDL where I didn't connect the XADC to anything other than the clk_100 (the 100 MHz clock signal) from Xillybus. I didn't even connect it to the FIFOs, it was just there sitting with Xillybus but with no connection to it, just like in my test project from before. And then I opened the Hardware Manager to monitor the XADC and then again, -273.1ºC and 0.00 V in all channels... I'm starting to think Xillybus is messing with the XADC some way I'm not aware of.
07-24-2017 09:17 AM
07-24-2017 09:29 AM
@hbucher I hadn't but I will do that soon. I'll send them an email and see if they can help me. As for now, I'll try using Xillybus Lite and see if that works. Anyway, if someone knows about this I'll be more than looking forward to hearing about it. Thanks for your your time hbucher.