Those pins are not connected to the external package. See page 4 of the Caravel datasheet here: https://github.com/efabless/caravel/blob/master/doc/caravel_

Those pins are not connected to the external package. See page 4 of the Caravel datasheet here: https://github.com/efabless/caravel/blob/master/doc/caravel_datasheet.pdf Only the digital I/Os are accessible from outside the package. Every entry in the table has either "power", "ground", or "digital {in,out,I/O}" for the "type" column. They appear to have some kind of simple output-only analog driver (see "analog output" in the Summary Description column) but no analog input according to the datasheet.