ADC presampling with bypass sampling enabled - Not working - EBTressos

[Venu_M]

Hi,

I am trying to perform ADC conversion for precision input and standard input channels for S32K342 device with the following configurations.

• Presample Enabled for each channel
• Bypass sample enbled for whole HW unit
• PREVAL - 0(VREFL)

Venukumar_0-1702621209869.png

OBSERVATION:

• Observed PREVAL values in result register for the respective ADC channels.
•  
  • if PREVAL - 1, Result registers are HIGH
    • Venukumar_2-1702621356140.png
  • if PREVAL - 0, Result register values are zeroes.
    • Venukumar_1-1702621281390.png
•  

[danielmartynek]

Hi @Venu_M,

This is a correct observation.

When PSCR[PRECONV] = 0, pre-samling is followed by sampling and conversion.

When PSCR[PRECONV] = 1, pre-samling is followed by conversion.

RM, Section 61.3.9 Presampling

danielmartynek_0-1702652656148.png

BR, Daniel

[Venu_M]

Hi @danielmartynek ,

I am trying to get correct conversion data with PSCR[PRECONV] = 1. Not able to get the correct data.

Regards,
Venu

[danielmartynek]

Hi @Venu_M,

These are the correct data.

When PRECONV = 1, the sampling on the actual input channels is skipped.

BR, Daniel