| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain prescribed erasing characteristics without rediffusion through change of mask and change of diffusion condition and to execute improving of productivity and shortening of developing time by controlling the voltage applied to the work line independently from outside. SOLUTION: Input terminals 112, 113 are provided to control independently from outside the voltage of work line of semiconductor memory unit having a CPU 101, a flash EEPROM 103, a port part 102 and a voltage circuit 104. By supplying 2 bits of data to the terminals 112, 113, the voltage of word line is set into four kinds. Thereby, even when the erasing characteristics (erasing speed, erasing variance, overerasing) are defective, the selection of voltage of word line enables obtaining prescribed characteristics. The terminals 105 are a plurality of terminals to input the mode signal, address and writing-in data or to output reading-out data required for erasing, writing-in and reading- out the flash EEPROM 103.</p> |
