I would like to operate peripherals on the kc705 FMC HPC connector at 3.3
V, both input and output. Can this be achieved by just setting the
IOStandard to LVCMOS33 in the fmc_adapter_io list in the gateware?
I ask because the kc705 manual states that all the I/O voltage rails are
set to 2.5V by default, including the FMC voltage rails. It also says that
to change FMC_VADJ to 3.3 V, you have to remove a jumper and reprogram some
TI controller. However, in the artiq gateware directory (e.g. nist_qc1.py),
I see LVTTL IOStandards, which means they're already operating at 3.3 V.
This is why I'm confused about what I need to do to work at 3.3 V off the
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