| 摘要 |
PROBLEM TO BE SOLVED: To provide a DMA diagnostic device capable of judging whether or not a data error is an error caused by the fault of a control part when it is generated. SOLUTION: The buffer 11 for data of a DMA diagnostic part 1 holds addresses and the data inputted by a DMA controller part 2 through a system and the buffer 12 for the data holds the addresses and the data outputted by the DMA controller part 2 through a memory bus. The DMA diagnostic part 1 compares the data held in the buffers 11 and 12 for the data and executes a diagnosis for the input/output data of the DMA controller part 2. When a diagnosed result is an error, the DMA diagnostic part 1 holds error information in an error register 13, disconnects access from the DMA controller part 2 where the error is generated by outputting bus changeover signals to a bus changeover part 4 and switches the access from a spare DMA controller part 3 to be valid. |
