US Patent 7869289 Semiconductor device having transmission control circuit

A semiconductor device has a transmission control circuit comprising a signal transmission circuit, an output control circuit, a replica circuit and a detection circuit. The single transmission circuit receives a predetermined signal in synchronization with a first control signal, and transmits and outputs the signal through a signal bus in synchronization with a second control signal. The output control circuit supplies the second control signal and controls an output timing thereof. The replica circuit transmits and outputs a replica signal (having level shifted in response to the input timing of the predetermined signal) through a replica signal bus having the same transmission characteristics as the signal bus. The detection circuit detects shifting of the replica signal and supplies a feedback signal to the output control circuit whose output timing is controlled in accordance with the shifting timing of the replica signal based on the feedback signal.