| 摘要 |
PURPOSE:To ensure the protective effect of a nonvolatile memory at the time of a supply voltage fall or power failure by adding a time to spare between the memory action of the nonvolatile memory and the resetting action of the microcomputer at the time of the voltage fall. CONSTITUTION:When the voltage of a power source 1 falls, the fallen voltage is immediately added to a detecting circuit 8, the inverted voltage is generated on an output side, a voltage change is generated at a power failure detecting terminal Vs of the microcomputer, and the memory action of the nonvolatile memory is carried out. On the other hand, the fallen voltage is applied through a diode 5 and a voltage stabilizing circuit 9 to a reset IC circuit 11, the microcomputer is made into a resetting condition with a time lag for the memory action of the nonvolatile memory. Thus, since the time to spare is added between the memory action of the nonvolatile memory and the resetting action of the microcomputer at the time of the voltage fall, the prescribed protective effect is surely attained. |
