| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory device in which bus width of a data line is reduced. SOLUTION: The device includes: a memory cell array; a data amplifier 1 that receives data read from the memory cell through a main data line MDQ; a DDR circuit 4 to which data output from the data amplifier 1 via a data selecting circuit 2 is input through a data line 3; and a data output circuit 5 that receives data output from the DDR circuit 4. In output lines of the main data line MDQ, the data line 3 and the DDR circuit 4, bus width is decreased stepwise from the data output circuit 5 side to the memory cell array side. In the output data selecting circuit 2 and the DDR circuit 4, input data is divided into two pieces of data, the divided data is time-divided to be output at a frequency twice an input frequency. COPYRIGHT: (C)2011,JPO&INPIT
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