open-source-silicon.dev

I have a stupid question :sweat_smile: 
Is user supply pin is a normal pin for supply?

Which supply pin?  There are always available `vccd1` and `vccd2` (1.8V power supplies), and `vdda1` and `vdda2` (3.3V power supplies), all fully ESD protected;  these are available on both caravel and caravan.  There are then three undedicated supply pins on caravan that can be used as power supplies (connect them to the associated clamp pins) or as signals (leave the associated clamp pins unconnected).

If l need , a supply pin for 14 volt supply what should I use?

You should use one of the straight-through analog signals, and design your own ESD circuitry (or assume the risk of an ESD-sensitive chip, with appropriate care in handling).

What's those pins? 
Where can I find total description for all pins in caravan?

The best documentation is the comments in `caravel_user_project_analog` in the file `verilog/rtl/user_analog_proj_example.v`.

You will want to use one of `mprj_io[14]` to `mprj_io[24]`, internally `user_analog[0]` to `user_analog[10]`.  If the pin is high current, then use `user_analog[4]` to `user_analog[6]`, which have a lot more metal around the pad for higher current density (connect to the pin with all three of metal3, metal4, and metal5).

If I want to use 4 pin high voltage and high current  , what should I use?

`mprj_io[18]`, `mprj_io[19]`, and `mprj_io[20]` are the pins that support high current.  Do not connect the clamp pins on those pads (or, you can tie them both off to ground).