SELECTING METHOD FOR SEMICONDUCTOR MEMORY CELL AND SEMICONDUCTOR MEMORY CELL SELECTOR CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent semiconductor memory cells more than two from being simultaneously selected. SOLUTION: When the signal of logic value High is outputted from the 1st input/output terminal of CPU 1 and the signal of logic value Low is outputted from the 2nd input/output terminal respectively, only a 1st EEPROM 2 outputs data corresponding to the output signal of selector circuit 5 and when the signal of logic value Low is outputted from the 1st input/output terminal and the signal of logic value High is outputted from the 2nd input/output terminal respectively, inversely, only a 2nd EEPROM 3 outputs data but when the signal of logic value High or Low is outputted from both the 1st and 2nd input/ output terminals, on the other hand, both the EEPROM 2 and 3 are turned to inactive state by the selection circuit 5.