| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently perform read processing, including even the time when an error occurs by using the memory unit having nonvolatile semiconductor memory to store sales data of such as an electronic money registering device. SOLUTION: An memory area (20) of this nonvolatile semiconductor memory is divided into 1st and 2nd areas (21) and (22). Sales data are successively written in data records 31a to 31e from a leading address of the area (21). Flags that show whether or not respective sales data writing is normally performed are written in flag areas 31af to 31ef. Sales data 'C' and 'E' in which a write error occurs are successively and newly written in the data records 32c and 32e from a leading address of the area (22). Because the data records 31a, 31b and 31d where no write error occurs can sequentially be read from the leading address of the area (21), data read can effectively be performed.</p> |
