| 摘要 |
PROBLEM TO BE SOLVED: To maintain as high a data rate as with DDR and input and output parallel data without being constrained typically by the number of external terminals. SOLUTION: The semiconductor memory device includes a plurality of pads 21, a memory core block 4, and an IO block 5. The IO block 5 includes a selection circuit 51 that mutually changes a combination of a data line and a pad connected to each other for each two data lines DL and two layered connection pads 21 of the memory core block 4 on the basis of an input address signal. The IO block 5 distinguishes which data lines DL the two data items D0 and D1 input or output via two pads 21 correspond to, based on the combination information. Thus, the data rate twice as high as the equivalent rate of the DDR is ensured. COPYRIGHT: (C)2011,JPO&INPIT
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