ADC+DMA First Conversion Timeout

JhonYF — Mon, 04 Aug 2025 01:59:39 GMT

MCU:s32k312

Problem Description:
When using ADC with DMA in group conversion mode, I'm observing a consistent issue where the first conversion start (Adc_StartGroupConversion) always results in a timeout condition. Specifically:

The group notification callback is never triggered
When polling the group status in a task, it remains stuck at "busy" indefinitely

If I execute a timeout handler (triggered by the initial failure), which calls Adc_StopGroupConversion followed by a second Adc_StartGroupConversion, subsequent conversions work flawlessly without any further issues.

Adc_StartGroupConversion(gularrMcuWrapAdcGroups[ulAdcIter]); Adc_StopGroupConversion(gularrMcuWrapAdcGroups[ulAdcIter]);

Question:

Has anyone encountered similar behavior where the first ADC group conversion fails (timeout/busy status) but works fine afterward?
Is this a known initialization sequence requirement for ADC+DMA groups (e.g., needing a dummy conversion to "prime" the hardware)?
Could this be related to clock gating, power-on state, or DMA initialization timing?

Looking for insights on root cause or recommended initialization practices to avoid this workaround.

topic ADC+DMA First Conversion Timeout in S32K

ADC+DMA First Conversion Timeout