pub struct In {}Expand description
This direction marker is used for a [Signal] that is an input with respect to a circuit. That means that we do not expect to write to the input, but that the value will be set by external components to the circuit.
use rust_hdl_core::prelude::*;
struct Foo {
    pub x: Signal<In, Bit>,     // <--- This is a single bit input
    pub y: Signal<In, Bits<8>>, // <--- This is a multi-bit input signal
}