| 摘要 |
PROBLEM TO BE SOLVED: To precharge a bit line in a short time prior to read operation of a memory cell by connecting the opposite ends of each bit line and specified word lines corresponding thereto with a pair of equivalent circuits, applying a specified constant voltage constantly to each of the specified word lines and controlling the equivalent circuit to apply a specified constant voltage across the bit line. SOLUTION: A pair of equalized circuits equivalent circuits 4 comprising transistors Q1, Q2 and Q3, Q4 are arranged at the left and right ends of bit lines BL1, BL2 and a precharge signal BLE is fed on word lines WL2-WL5 while a precharge voltage 1/2 Vcc is applied constantly to word lines WL1-WL6. The precharge signal BLE goes H prior to read operation and the transistors Q1-Q4 are turned on concurrently. According to the arrangement, the bit lines BL1, BL2 can be initialized in a short time by applying the precharge voltage 1/2 Vcc concurrently from the opposite sides. |
