Patent ID: 7518940

Claim:
A driving method of a memory device for escaping from a power-down mode in response to a power-up signal and a clock enable signal at an initial setting starting a supply of supply voltage, comprising: setting the power-down mode at the initial setting starting the supply of the supply voltage; latching a inactivated state of the clock enable signal in response to the power-up signal which is used a reset signal of a latch; combining a activated state of the clock enable signal and a previously latched state of the clock enable signal when the clock enable signal is activated; outputting a power-down mode exit signal in response to the combined result of the previously latched state of the clock enable signal and the current activated state of the clock enable signal; escaping from the power-down mode in response to the power-down mode exit signal; and interrupting in input of the clock enable signal when the memory device escapes from the power-down mode.