| 摘要 |
PROBLEM TO BE SOLVED: To judge whether or not a data error is generated due to the failure of a control part or the failure of a DRAM single body by allowing a DAM diagnosing part to separately detect the failure of a DMA controller part and the failure of plural DRAM. SOLUTION: DRAM 6a-6c are provided for each of plural banks, and DMA transfer to the prescribed DRAM among the DRAM 6a-6c is controlled by a DMA controller part 4 based on a DMA request signal 10 and data and an address transferred through a system bus 11. Bus switching parts 5a-5c switch the connection of the DRAM 6a-6c with a DMA controller part 4, and a DMA diagnosing part 1 detects the failure of the DMA controller part 4 and the DRAM 6a-6c. A DMA controller diagnosing part 2 of the DMA diagnosing part 1 detects the failure of the DMA controller part 4, and a DRAM diagnosing part 7 of the DMA diagnosing part 1 detects the failure of the DRAM 6a-6c. |
