NONVOLATILE SEMICONDUCTOR MEMORY

摘要

PURPOSE:To decrease the number of a pump-up by inputting drive controlling clocks of a boosting circuit for boosting word lines at the time of a read-out in the period of a precharging. CONSTITUTION:A signal phi PR (voltage rising circuit driving clock) for setting pump-up timings and a clock generation circuit CKU generating a precharge transistor controlling clock BPR for a precharging at the time of the read-out, a discharge transistor controlling clock DIS for controlling a discharging are connected to a boosting circuit VPU by which a boosted voltage VBB is generated. Timings of respective controlling clocks are so constituted in the circuit that the timing for the DIS is earlier than the changing point of a level of the BPR being the beginning of the read-out and the boosting circuit driving clock phiPR is more ealier than the timing for the DIS.