Semiconductor device and semiconductor chips outputting a data strobe signal

A semiconductor chip that outputs a data signal and a data strobe signal indicative of an output timing of the data signal,

• said semiconductor chip comprising:
• a strobe signal control unit that determines whether an other semiconductor chip connected in parallel with said semiconductor chip is in a read state, and delays an output start timing of a data strobe signal when it is determined that said other semiconductor chip is in the read state.

A semiconductor device comprising:

• a plurality of semiconductor chips mounted thereon, said semiconductor device outputting a data signal and a data strobe signal indicative of an output timing of the data signal from said semiconductor chips,
• wherein one of said semiconductor chips comprises:
• a strobe signal control unit that determines whether another one of semiconductor chips is in a read state, and, when it is determined that said another one of semiconductor chips is in the read state, controls an output start timing such that a latter half portion of a preamble period of the data strobe signal to be output coincides with a postamble period of the data strobe signal output by said another one of semiconductor chips and that a former half portion of the preamble period is kept in a high-impedance state.

A semiconductor chip that outputs a data signal and a data strobe signal indicative of an output timing of the data signal, said semiconductor chip comprising:

• a strobe signal control unit that determines whether another semiconductor chip connected in parallel with said semiconductor chip is in a read state, and, when it is determined that said another semiconductor chip is in the read state, controls an output start timing such that a latter half portion of a preamble period of the data strobe signal to be output coincides with a postamble period of a data strobe signal output by said another semiconductor chip and that a former half portion of the preamble period is kept in a high-impedance state.