A semiconductor device includes a first controlled chip and a control chip stacked therewith. The first controlled chip includes a first circuit outputting a data signal in response to a synchronization signal, an input/output circuit outputting the data signal to a data terminal in synchronization with a delayed synchronization signal, and a replica circuit replicating an output circuit and outputting a replica signal to a first replica terminal in synchronization with the delayed synchronization signal. The control chip includes a first control circuit outputting a synchronization signal and receiving a data signal, a delay adjustment circuit delaying the synchronization signal and outputting the same as a delayed synchronization signal, a phase comparator circuit comparing the phases of the replica signal and the synchronization signal, and a delay control circuit controlling the delay amount of the delay adjustment circuit based on a comparison result of the phase comparator circuit.