| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a semiconductor memory device which includes a plurality of memory units and can suppress a power supply noise by making an execution timing of refresh operation to be different for each memory unit. <P>SOLUTION: A common internal clock CLK is input to a plurality of DRAM memory units 2-1 to 2-n, and each of the DRAM memory units 2-1 to 2-n includes a DRAM memory cell array 52, a control circuit 51 for controlling an operation of the memory cell array 52 based on the internal clock CLK, and a delay circuit 53 for delaying the input internal clock CLK to input it to the control circuit 51. In the refresh operation, by the delay circuit 53 in each of DRAM memory units 2-1 to 2-n, the input internal clock CLK is input to the control circuit 51 by making a delay amount to be different for each of DRAM memory units 2-1 to 2-n. <P>COPYRIGHT: (C)2011,JPO&INPIT |
