| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an effect due to dispersion in coupling capacitance by short-circuiting a bit line of a data side corresponding to a precedently read bit with the bit line of a reference side corresponding to a next read bit until the next read data are read after the precedently read data are read. SOLUTION: The data by two bits are stored in one memory cell, and respective higher rank data and lower rank data are read out by two pieces of sense amplifiers SA0: 10, SA1: 11. After a word line WL: 12 is activated, and a signal is outputted to bit lines 21, 23, a switch 28 is turned off, and a data signal read out to the bit line 21 is sensed by the sense amplifier SA0: 10, and higher rank bit side pairs 21, 22 are made to swing fully. Then, the switch 27 is turned off, and the SA0: 10 is separated from the higher rank bit side bit line pairs 21, 22. Then, the switch 26 is turned on, and the bit line 21 of the higher rank bit side bit line pair is short-circuited with the bit line 24 of the reference side of a lower rank bit side, so that the potential of the bit line 24 is changed.
|
