| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To allow an abnormality in DMA to be detected and memory overwrite to be minimized, when a transfer destination address error occurs in a DMA transfer operation, and unauthorized DMA accesses are made to an unforeseen memory area. <P>SOLUTION: A controller having a DMA (direct memory access) function includes a memory area A121 which is a transfer destination for a DMA device A13a; a memory area B121a in which an initial value of a timer A14a is stored; a timer A14a which causes time-out at a predetermined time; a timer B14b, which generates a start request signal for a DMA device B13b, at a predetermined time interval that is shorter than the time-out time of the timer A14a; and a DMA device B13b, which transfers the value of the memory area B121a to a counter of the timer A14a and initializes the timer. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
