| 摘要 |
PURPOSE:To improve the reliability of a semiconductor disk device by decreasing the number of error parts included in the data to undergo an ECC operation down to only one or less. CONSTITUTION:A date string 101a stored in the higher order bit side of the first row of a flush EEPROM 11 and a data string 101b stored in the lower order bit side belong to the ECC operational groups A and B respectively. Meanwhile a data string 102a stored in the higher order bit side of the second row of the EEPROM 11 and a data string 102b stored in the lower order bit side belong to the ECC operational groups B and A respectively. In such a constitution, only one defective cell is included in each ECC operational group even though the defective cells occur at the same bit positions of plural rows of the EEPROM 11. As a result, the data can be easily recovered by the ECC. |
