| 摘要 |
PURPOSE:To eliminate the stopping of a system due to a reading error by dividing the memory area of a memory by an address, storing copied data to each, changing the memory area to read the data when an error is found in read out data to enable to take out normal data. CONSTITUTION:11a-11d are memory areas in which the same data are written, 12a-12d are pointers that show the respective head address of the memory areas 11a-11d and 13 is a control circuit that selects one of pointers 12a-12d. An address 3 is inputted to a memory 1 by a memory read 7, and at the same time, a pointer 12a is selected by the control circuit 13, and data are read from the memory area 11a. At this time, when no reading error in judging process 8 is found, it is recognized as normal operation to move to the processing 9 of normal operation. When a reading error is found, the control circuit 13 selects a pointer 12b, and the same data are read out from the memory area 11b. |
