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Hello everyone, it says that there are 38 I/O in Caravel, but I cannot understand this. For example, I want to use io_in[0], but since I do not drive io_out[0], yosys gives an error. How would I use ports for input and output. Thanks in advance.

(You're better off posting to <#C01EX4ATEKF|caravel> since posts to <#C016G7Z8GDR|general> have a low signal-to-noise ratio.)

I don't really understand why yosys would be giving you an error if you don't drive `io_out`.  However, all GPIOs are a 3-pin interface with `io_in`, `io_out`, and `io_oeb`, so the "best practice" way of connecting it if you are using only the input would be to set the corresponding `io_oeb` to 1 (output disabled), and set `io_out` to 0 (just so it isn't floating).