Inside receives the automatic precharge device null bank address and the external refuse instruction signal

摘要

An auto precharge apparatus having an auto precharge gapless function protecting circuit in a semiconductor memory device which can prevent an externally-inputted illegal command from being executed, by disabling a row active peri signal earlier than a row active core signal in an auto precharge operation. The auto precharge apparatus includes: an internal cas command signal generator for receiving a bank address and an external cas command signal, and generating an internal cas command signal; a burst length counter for receiving the internal cas command signal and a burst stop signal, and generating a burst end signal representative of an end of a burst operation; an auto precharge signal generator for receiving the burst end signal, the internal cas command signal, an auto precharge end signal and an external address, and generating an auto precharge peri signal and an auto precharge core signal; and an internal row active signal generator for receiving the auto precharge peri signal, the auto precharge core signal, a precharge signal and an externally-inputted row active signal, and generating a row active peri signal and a row active core signal.