Xavier OEM says PCIe RESET_N, CLKREQ, and WAKE_N signals are “CMOS – 1.8V”.
I also read through Xavier devkit schematic. I can see that they are directly connected to M.2 M key and M.2 E key connectors WITHOUT going through any voltage level shifter.
- Should these signals converted from 1.8V to 3.3V using level shifter, and then connected to M.2 M/E key?
- What’s the PCIe standard requirement on voltage level of these pins?
- Is the expected voltage level dependent on the device connected on M.2 M/E key? (e.g. NVMe SSD, or wifi chip) I highly doubt that it is device dependent, because it should follow a “universal” standard.