| 摘要 |
PURPOSE:To improve the DMA system efficiency by mixing in a prescribed ratio both the bus conflict control which acquires the bus use right after stopping a processor and the bus conflict control which acquires bus use right after the end of a processor cycle. CONSTITUTION:A bus conflict means 15 allows the use of a bus to an input/ output device when a bus use request is received from the input/output device and at the same time outputs a stop request to a processor to confirm the unused state of the processor when a start signal is outputted from the input/ output device for use of the bus. While a bus conflict means 16 confirms the unused state of the processor when a start signal is outputted from the input/ output device and allows the use of bus to the input/output device. Both means 15 and 16 are switched by a switching means 14 in a prescribed ratio for execution of the conflict control. |
