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- Problem
If I take statistics over the ADC results (connected to a fixed voltage; only noise) I get nearly pure even results.
I get less than 1/1000 of odd conversion results. When measuring under noisy conditions, I expect an equal distribution of even and odd values.

Are the registers initialized correctly(I attach screenshots)? Is there another pitfall in the initialisation sequence?

- Configuration
Controller XMC4400 F100K512 AB
ADC is triggered by CCU8 every 10 µs
All 4 ADCs are triggered synchronously (group 0 as master) and are configured to take Ch0 and Ch1

My code is based on the example Dave4_VADC-XMC4000-AP32305_Example_Code Example 6 "06_VADC_Synchronous_Conversions_Queue_Source"
I consider this example to be faulty since it starts the ADC before configuring the link between the groups in the Synchronization Control Register
while the documentation states: "Set the master’s GxARBCFG.ANONC at the end of the initialization."

- Unfortunately it is not possible to search the forum for "vadc":
Result is: "The following words are either very common, too long, or too short and were not included in your search: 'vadc'"
So I am not sure if the problem was answered before.

Thank you,

1 Reply
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First solution authored Welcome! 500 replies posted

You might want to reference the attached software for XMC4500 which you can reuse the source file VADC.C ... etc for XMC4400.


Beside this, adding a capacitor like below might help.