The SN54CBT16209 and SN74CBT16209A devices provide 18 bits of high-speed TTL-compatible bus switching or exchanging. The low on-state resistance of the switches allows connections to be made with minimal propagation delay. The devices operate as an 18-bit bus switch or a 9-bit bus exchanger, which provides data exchanging between the four signal ports via the data-select (S0, S1, S2) terminals.