| 摘要 |
PURPOSE:To reduce the capacity of a backup power source by storing the state of an arithmetic part, turning the power source off when any abnormal operation is executed and afterwards, displaying a message to inform the execution of the abnormal operation when the power source is turned on. CONSTITUTION:For example, when a battery 3b is suddenly deteched or an IC card is loaded/unloaded during the operation, this is detected by a detection circuit 11, and the detection signal is outputted through an interface 2 to a CPU 4. At this time, the CPU 4 controls a power supply circuit 3 and turns the power source off. Thus, when a user turns the power source on again after it is turned off in the state of emergency, the message to inform the occurence of the abnormal operation is displayed. Namely, since only the state of the CPU 4 is saved in the case of generating any abnormal condition and the other required processings are executed after the power source is turned in, it is sufficient for a capacitor 3a for backup of the power supply circuit 3 to back up the device only for several 10mus. Therefore, large capacity such as a super capacitor is not required. |
