A multi-rank circuit system utilizing a shared IO channel includes a first stage of multiple selectors coupled to input multiple digital busses, and a second stage including one or more selectors coupled to receive outputs of the first stage of selectors and to individually select one of the outputs of the first stage of selectors to one or more control circuits for IO circuits of the ranks. The system switches one of the ranks to be an active rank on the shared IO channel, and operates the first stage of selectors to select one of the digital busses to the second stage of selectors in advance of switching a next active rank to the shared IO channel.