Internal clock generating circuit and method for generating internal clock signal with data signal

Abstract

An internal clock generating circuit and a method for generating an internal clock signal are disclosed. The internal clock generating circuit includes a transition detecting block for detecting transitions in a data signal and generating data transition information, and an internal clock generating block for generating and storing a period digital data while detecting the unit period of the data signal in a period confirming mode. In the internal clock generating circuit, the internal clock signal can be generated without the external clock signal, so that the internal clock generating circuit can be implemented with a simple constitution. Additionally, an extra locking time is not required for locking the extra clock signal, so that the operating speed of the internal clock generating circuit is improved. The internal clock signal is dependent on the data signal, so that it is easy to control the set-up and hold for data.