| 摘要 |
PURPOSE:To check the troubled state of a RAM at a high speed by accessing directly the RAM with the DMA transfer and performing the comparison of data with the hardware. CONSTITUTION:A direct memory access device DMA is provided together with a generating means for data to be compared which outputs the data to be compared onto a data bus with the signal supplied from the DMA based on the data fed from a central processing unit, a comparison data generating means which produces the comparison data based on the data fed from the central processing unit and a comparator which has two data input sides connected to the data output side of the comparison data generating means and the data bus respectively and compares these two data with each other. The output of this comparator is used for control of the DMA or the central processing unit. Thus a comparison operation of a matching method, the address calculation and a memory access can be executed with no intervention of a CPU. |
