| 摘要 |
PURPOSE:To increase the component density of a memory cell when a complete CMOS type static RAM is composed by composing a basic cell of four first conductivity type MOS transistors and four second conductivity type MOS transistors. CONSTITUTION:A basic cell is composed of four p-channel MOS transistors Q1-Q4 and four n-channel MOS transistors Q5-Q8. Here, the W/L of the transistors Ql-Q4 are the same, and the W/L of the transistors Q5-Q8 are also the same. The memory cell of a complete CMOS static RAM can be composed of one basic cell. In this case, the two p-channel MOS transistors of the cell are not used but excessive, but the unused transistors merely occupy about 1/4 of the cell. Accordingly, the using efficiency of the cell is higher than the case in which the memory cell of the complete CMOS static RAM is composed.
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