The number of lines needed to establish bidirectional communication depends on the specific protocol too. Since one wire can only transport one bit of information in one direction at a time, to achieve full-duplex communication, a transceiver should connect to two different wires for transmitting and receiving data. If the protocol supports half-duplex communication, it should instead provide a reliable mechanism to regulate media access and switch between receiving and transmitting data on the same wire.
Depending on the protocol, devices accessing the bus may either share a similar implementation and act as peers, or have different roles assigned when participating in the communication, for example, if a master device is in charge ...
