ADC overrun

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by IanB on Thu Dec 17 13:55:28 MST 2015
I have an application where the ADC is set to runs continuously. It reads 6 channels, 10 bits per channel, with a division ratio of 56. With a 48MHz clock the sequence repeats 13000 times a second.
The interrupt is triggered by the end of the conversion on AD7, and the routine reads all the data registers (not the global data register - I have read the errata)

Although the data seem correct, every channel has bit 30 set indicating an overrun.

I even reduced the interrupt service routine so that it did no more than read the data registers and toggle a GPIO port.
I could see on the 'scope that it was running 13000 times a second, but it still indicated overruns on each channel.

Should I just ignore bit 30? Or has there really been an overrun?