Intel® Pentium® Silver and Intel® Celeron® Processors Datasheet, Volume 1
Configurable GPIO Voltage
Except for all pads in GPIO F, GPIO S, and GP_DSW groups, all other GPIO pads support per-pad configurable voltage, which allows control selection of 1.8 V or 3.3 V for each pad. The configuration is done via soft straps.
Before soft straps are loaded, the default voltage of each pin depends on its default as input or output.
- Input: 1.8 V level with 3.3 V tolerant.
- Output: the pin drives 3.3 V via a ~20 K pull-up. With this, any 1.8 V device must be capable of taking 20K pull-up to 3.3 V.