Semiconductor memory device with mode register and method for controlling deep power down mode therein

摘要

Disclosed are a semiconductor memory device with a mode register that prevents the semiconductor device from undesirably entering into a deep power down mode during the beginning of a power up and a method for controlling a deep power down mode therein. An internal power supply voltage generator generates an internal power supply voltage of the semiconductor memory device. A clock buffer buffers external clock and clock enable signals to generate internal clock and clock enable signals. A command decoder generates an intermediate deep power down mode entry signal or a mode register setting signal. A mode register setting latch circuit latches the mode register setting signal from the command decoder. A deep power down mode controller generates a final deep power down mode entry signal. A semiconductor memory device is accordingly prevented from undesirably entering into a deep power down mode during beginning of a power up.