Memory device transmitting and receiving data at high speed and low power

A method for using a high bandwidth memory controller includes providing a clock signal having a first clock frequency, providing a write strobe signal having a second clock frequency, providing a write command/address signal based on the clock signal, and providing a write data signal based on the write strobe signal. The first clock frequency is half of the second clock frequency, the write strobe signal has two cycles of pre-amble before the write data signal, and the write strobe signal has two cycles of post-amble after the write data signal.