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Re: Re(2): External DMA interrupts
I will see if I can draw any further conclusions, but I can at least
answer two things directly:
> The descriptor status byte isn't updated after the transfer.
Descriptors are updated by the DMA only for input channels, not
for output channels.
> > > The internal DMA has a register to get the reason for the interrupt.
> > > Where is the data for the external DMA ?
> > There is only one reason: The channel is stopped. Se above for
> > reasons for stopping. DREQ inactive does not stop the channel,
> > it just "pauses" it.
> Does this means that when the IO drops DREQ the run bit in
> R_EXT_DMA_0_STAT is still 1 ?