Cellular phone, and data protection method and program thereof

A flip cellular phone having a casing to be folded, comprising:

• a nonvolatile memory means;
• detection means for detecting a residual amount of a battery;
• and
• control means for transferring data to be protected to the nonvolatile memory means by folding the casing,
• wherein the control means checks presence of changes in a content of data stored in the nonvolatile memory and a content of data to be currently protected before the data to be protected are transferred to the nonvolatile memory means when a residual amount of the battery detected by the detection means drops below a predetermined amount, and the control means transfers the data to be currently protected to the nonvolatile memory when a change of the data to be protected is determined-.

A flip cellular phone having a casing to be folded, comprising:

• a nonvolatile memory circuit;
• a detection circuit for detecting a residual value of a battery;
• and
• a control circuit for transferring data to be protected to the nonvolatile memory circuit by folding the casing,
• wherein the control circuit checks presence of changes in a content of data stored in the nonvolatile memory circuit and a content of data to be currently protected before the data to be protected are transferred to the nonvolatile memory circuit when a residual amount of the battery detected by the detection circuit drops below a predetermined amount, and the control circuit transfers the data to be currently protected to the nonvolatile memory circuit when a change of the data to be protected is determined.

A data protection method in a flip cellular phone, comprising steps of:

• detecting that a residual amount of a battery has become equal to/lower than a predetermined value;
• checking a difference between data to be currently protected and past data after the step of detecting;
• and
• transferring the data to be protected to a nonvolatile memory only when a difference of data is determined.