产生中断的目的是要通知 CPU ,DMA 不需要再占用系统总线了,就是把DMA ASK 置零是吗?或者就是在中断里面把DMA chanel 关掉! 是这样吗?
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DMASKTRIG1 的ON_OFF bit 在DCON[22] bit is "no auto reload", 的时候 becomes 0 when CURR_TC reaches 0. If the STOP bit is 1,
我主要在写数据程序里面等待数据传递完毕,即CURR_TC reaches 0,那么DMA chanel 就会自动为0,
我就不需要利用中断来做这个工作了???
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TRANSMITTING PROCEDURE FOR DMA
1. SPI is configured as DMA mode.
这个好做
2. DMA is configured properly.
这个怎么设置
3. SPI requests DMA service.
4. DMA transmits 1byte data to the SPI.
5. SPI transmits the data to card.
6. Return to Step 3 until DMA count becomes 0.
7. SPI is configured as interrupt or polling mode with SMOD bits.