| 摘要 |
In foldable cellular phone, when a casing opening/closing detection circuit detects folding of the casing, a control circuit transmits an interruption signal to the CPU. Upon reception of the interruption signal the CPU backs up data in a RAM to a non-volatile memory such as a FLASH ROM. In addition when the battery level drops below a predetermined threshold level, data is backed up to the FLASH ROM. The CPU may compare the data in the RAM with the data in the FLASH ROM and back up the data only if there is a difference between the two. The lifetime of the FLASH ROM is therefore prolonged. The cellular phone also has a locking mechanism which is activated to prevent the battery from falling off or being removed when the casing is open, and deactivated when the casing is closed. |
