I'm sorry for the layout. The code was supposed to be displayed as code.
And of course many thanks in advance!
I found the solution!
I don't know if it's an internal bug with the memory mapping but it seems like it.
After checking every possible source and reading tons of paper about the DMA, I still couldn't find any solution. I couldn't explain why it stopped after 230 seconds and why it stopped at all.
My idea was, that the DMA isn't able to map the destianation address properly and therefore hangs after some time. Maybe it's in the memory nirvana and doesn't find a way out.
I then tried to change the SPS from the ADC into a by-8-devidable figure. I changed it from 182250 to 182248. And these two little samples solved my problem! Maybe there are more, who experienced a similar problem and didn't know how to fix it.
When you observe this 'stop' condition, does the ADC still generate end-of-conversion pulses?
What do you do in the IRQ handler which gets triggered when the 50 bytes are read? Do you re-start the DMA then? (the DMA configuration doesn't loop the TD to itself, so it will stop after 50 bytes)