Paul Chang Posted September 16, 2020 Share Posted September 16, 2020 Dear Sir, I have a question about io voltage test. Our Configuration : NEXYS Video board + Xilinx FMC XM105 debug board. We set up IO to 1.2V , IO add a pull-up to 3.3V IO is set to output and logic 1 => voltage at this point: 1.2V =>OK IO is set to output and logic 0 => voltage at this point: 0V => OK IO is set to High-Z => The voltage at this point is about 2V IO is set to input => the voltage at this point is about 2V => Are them correct? Best Regards, Paul Link to comment Share on other sites More sharing options...
zygot Posted September 16, 2020 Share Posted September 16, 2020 1 hour ago, Paul Chang said: We set up IO to 1.2V , IO add a pull-up to 3.3V Do you mean that your design constraints uses the 1.2V LVCMOS_12 IOSTANDARD for your outputs? I hope that you aren't using external pull-up resistors to 3.3V on your outputs. Did you intend to say that your constraints selected internal pullups to Vccio? Did you make sure that you properly set the Vccio bank voltage for your FMC IO to 1.2V using the pins described in the Nexys Video Manual? Link to comment Share on other sites More sharing options...
Paul Chang Posted September 18, 2020 Author Share Posted September 18, 2020 Hi @zygot We know the root cause, Thanks for your answer. Best Regards, Paul Link to comment Share on other sites More sharing options...
Question
Paul Chang
Dear Sir,
I have a question about io voltage test.
Our Configuration : NEXYS Video board + Xilinx FMC XM105 debug board.
We set up IO to 1.2V , IO add a pull-up to 3.3V
IO is set to output and logic 1 => voltage at this point: 1.2V =>OK
IO is set to output and logic 0 => voltage at this point: 0V => OK
IO is set to High-Z => The voltage at this point is about 2V
IO is set to input => the voltage at this point is about 2V => Are them correct?
Best Regards,
Paul
Link to comment
Share on other sites
2 answers to this question
Recommended Posts
Archived
This topic is now archived and is closed to further replies.