Artix-7 I/O pull down resistor after startup

[phenry]

When looking through the datasheet for packaging and pinout, I found an option to enable pullup resistors on I/Os after startup and during configuartion by using the PUDC_B pin. I was wondering if there was a way to pull all of my I/Os down after startup and during configuration. Pulling the PUDC_B pin high only disables the pullup resistors, which leaves the I/Os floating at startup and during configuration. How do I resolve the issue of the floating I/Os?

[lowearthorbit · Accepted solution]

You may

pull up, or pull down after configuring.

Before configuration, while powering up and configuring, there is only the pull up option you already mentioned.  By design, all IO are tristate before DONE is asserted.  So, you should use external resistors where needed.

l.e.o.