| 摘要 |
PROBLEM TO BE SOLVED: To improve the throughput of system in a static RAM(SRAM) cell small in area by conducting a reading and a writing in one cycle to a small cell in a SRAM type semiconductor memory and simultaneously conducting a two port operation of a reading and a writing in a one cycle required for a reading. SOLUTION: In this semiconductor memory, a memory cell array 10 is constituted of one port SRAM cells. Word lines WL are activated twice in one cycle during only a certain period for a reading using a first clock edge as a reference and for a writing using a second clock edge as a reference. Data read from a memory cell by a first time word line WL activation are transmitted to a sense circuit 30 and bit line pair BL and BLB and the circuit 30 are cut by a sense circuit cutting switch 35. Then, a writing control switch 55 is turned on, writing data are transmitted to bit line pair BL and NBL and data are written into the memory cell by second activation of the lines WL.
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