Patent ID: 8010739

Claim:
An electronic device connectable to an electrically data-rewritable nonvolatile memory, in which predetermined data have been written in advance, for executing processing based on the data stored in the nonvolatile memory, comprising: storage means capable of temporarily storing the data stored in the nonvolatile memory; data updating means for updating the data stored in the nonvolatile memory by executing data update processing of reading out the data stored in the nonvolatile memory from the nonvolatile memory and storing the data read out from the nonvolatile memory in the storage means, and rewriting the data stored in the storage means into the nonvolatile memory; after-writing time passage estimation means for estimating the passage of time after writing which is the passage of time after a moment the data stored in the nonvolatile memory are written into the nonvolatile memory; update control means for having the data updating means execute the data update processing every time when the passage of time after writing estimated by the after-writing time passage estimation means exceeds a threshold value; and a slot portion to which a memory card including the nonvolatile memory is detachably connectable, the electronic device being connectable to the memory card via the slot portion to execute the processing based on the data stored in the nonvolatile memory included in the memory card, wherein the after-writing time passage estimation means estimates the passage of time from a moment the data update processing is executed by the data updating means, as the passage of time after writing, and wherein, if the data update processing has not been executed in the past for the nonvolatile memory included in the memory card, the after-writing time passage estimation means estimates the passage of time from a moment the memory card was connected for the first time to the slot portion, as the passage of time after writing.