| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having a new structure, which can hold a memory content and has no limits in rewritable times even in a situation where power is not supplied.SOLUTION: The semiconductor device comprises a nonvolatile memory cell including a transistor 162 for writing using an oxide semiconductor, a transistor 160 for reading using a semiconductor material different from that of the transistor 162 and a capacitance element 164. Writing into the memory cell is performed such that by turning on the transistor for writing, potential is supplied to a node where a source electrode (or a drain electrode) of the transistor for writing, one of electrodes of the capacitance element and a gate electrode of the transistor for reading are electrically connected, and subsequently by turning off the transistor for writing, the node is caused to hold a predetermined quantity of electric charge. By using a p-channel type transistor as the transistor for reading, reading potential becomes positive potential. |
