| 摘要 |
PURPOSE: To ensure the recovery of important data even when failure is present in a device by storing the important data in a second address obtained by inverting a first address, and reading the data in the case of the error of an address line. CONSTITUTION: Each data word stored in a column 30 is stored as plural binary bits such as 00001111 at first, and then stored in a logically inverted form, that is, like 11110000. Thus, at the time of reading the data from the first 4 lines in the column 30, a data line whose reading level is always a high or low level can be the cause of an error, and even in this case, at the time of reading the same data stored in the logically inverted form again, the important data can be correctly read. Also, each data word stored in the column 30 in the logically inverted form is stored also in an address obtained by logically inverting the address of the original data in the logically inverted from. |
