| 摘要 |
PROBLEM TO BE SOLVED: To properly perform access to a nonvolatile memory by eliminating problems caused by the voltage variation, etc., of an operation power source. SOLUTION: An electronic controller 10 is provided with a power source circuit 11 for generating prescribed constant voltage Vcc from a battery power source, a microcomputer 12 and an EEPROM 13 (nonvolatile memory) connected with the microcomputer 12 in the state of being capable of communicating data. The circuit 11 monitors the battery power source and outputs the judging result to the microcomputer 12 from an LVG terminal. The Vcc terminal of the EEPROM 13 is connected to that of the circuit 11 through a control switch 15. When a main switch 17 is on, the microcomputer 12 turns on/off the switch 15 in accordance with the necessity of access to the EEPROM 13. In this case, only in the data access of the EEPROM 13, the switch 15 is turned on to supply Vcc to the EEPROM 13. |
