Strange INT timing
I tried to find out a problem for long long days without result. May be someone has the same.
I have an ADC with SPI. I use 1200 sample/sec. I use DMA with 2 CH. It works well until I enable the RTC IC on I2C. After enabling sometime the sample/second value goes up to ~40000. The DMA transfer starts with Change Notification, INT priority 5. This is the only interrupt on this level. The DMA block complete (SPI RX) interrupt is on level 6, this is the only interrupt on this level also.
I can't figure out what is modifying the timing of the interrupt.