Synchronous semiconductor memory device

摘要

A synchronous semiconductor memory device has a memory section which includes a memory cell array having a plurality of memory cells and which is capable of a read operation of reading information from the memory cells according to a read command and a write operation of writing information into the memory cells according to a write command. The synchronous semiconductor memory device further has a command sensing circuit which senses whether a first command inputted in synchronization with an external clock signal is the read command or the write command. The synchronous semiconductor memory device further has a bank timer circuit which, when the command sensing circuit has sensed either the read command or the write command, sets the end time of the restore operation of a row address strobe (RAS) and the start time of the precharge operation of the RAS according to the external clock signal.