| 摘要 |
PURPOSE:To prevent erroneous write, and to shorten the erasing time by providing a high-voltage setting means through which the potential of a bit line at the time of erasing is made higher than that of a word line and a bit line at the time of write. CONSTITUTION:Two charging pumps are installed, and output voltage from the charging pump 32 generating high voltage Vpp (BL, E) applied to bit lines is set at a value higher than output voltage from the charging pump 11 generating high voltage Vpp (WL, P) applied to word lines. High voltage Vpp (WL, P) generated by the charging pump 11 is transmitted over the word line selected by a high-voltage switch 14. A signal E rises on erasing, and output voltage from the charging pump 12 is transmitted over the bit lines through an I/O line 20. A signal P rises on write, and voltage applied to a Vpp terminal (an external high-voltage input terminal) T1 is transmitted over the bit lines. |
