Cyclone 10GX VREF pin

Ad13 · ‎01-15-2021

I have a custom board using Cyclone 10GX085YU484 and I cannot program the device and it does not appear on the JTAG chain. I have left the VREF pins floating (VREF pins (T7, T13, J15 and F12) ). The datasheet says these should be connected to VCCIO or GND. Could this error stop the FPGA from running up and being programmed (visible on JTAG)? Same with VREFP_ADC and VREFN_ADC (floating and should be GND). Thanks.

AminT_Intel · ‎01-17-2021

Hello,

I believe this could be because of connection error. Can you confirm if your device is connected to your computer? Could you use other plugs to confirm that?

Thank you.

Ad13 · ‎01-18-2021

Hi, yes all connected to Quartus and the Quartus programmer.

I have tried multiple programmers(download cables), including the official Altera USB Blaster 2. I am able to program other devices from Quartus with the same set up and download cable fine.

Would floating VREF pins cause this problem?

Thanks.

AminT_Intel · ‎01-18-2021

You may a receive this error message during auto-detect possibilty due to a download cable problem, TDO is not connected properly, a noisy TCK signal, or TDI shorted to GND.

Here are some suggested steps for resolving the issue:

Make sure the pull-up and pull-down resistors connected to the JTAG pins are following the recommended values as stated in the respective device handbook.
Check the JTAG chain connectivity and the integrity of the TCK signal. Altera recommends pulling the TCK pin low through a pull-down resistor. Also make sure the TCK signal is clean to avoid any programming or JTAG configuration failure.
Use another USB-Blaster™ or other download cable. This is to ensure that the download cable is functioning.
Check the voltage seen on the pins of the JTAG header to see if they are at appropriate levels. The download cable is powered by the board, so ensure your board is properly powered.
Ensure all power supplies to the device are within recommended operating conditions. Refer to the respective device handbook for the correct voltage level.

Thank you.

L982123 · ‎01-19-2022

Hi, were the floating VREF pins causing your problem? I am seeing the same issue and VREFs also floating.