REFRESH CONTROL CIRCUIT OF A SEMICONDUCTOR MEMORY APPARATUS

摘要

According to the present invention, a refresh control circuit of a semiconductor memory device includes: a refresh mode defining unit which outputs a refresh mode signal in response to an external input; an automatic speed switching unit which outputs a high speed enable signal with a constant pattern in response to a refresh signal and the refresh mode signal; and a refresh control unit which controls the number of refreshed memory cells per one refresh command according to the high speed enable signal in response to the refresh command once or more times and outputs the refresh signal.