| 摘要 |
PURPOSE:To obtain a semiconductor integrated circuit device having backup identification function by providing a complementary MOS inverter circuit comprising a P-channel MOSFET and an N-channel MOSFET. CONSTITUTION:The complementary CMOS inverter circuit activated by the same power supply voltage as that for an internal circuit (static RAM, SRAM) and comprising the P-channel MOSFETQ3 and the N-channel MOSFETQ4 is provided. When a system power supply voltage Vcc is applied, since the level of the input to the CMOS inverter circuit is brought into a high level via a Q1, its output signal goes to a low level. Thus, the output signal of an OR gate G1 is brought into a level according to the level of a chip selection signal CS. When the power supply is interrupted, the output signal of the CMOS inverter circuit goes to a high level, the chip selection signal is brought forcibly into the chip non-selection state of high level to attain backup. |
