topic S32K ADC + DMA + PDB trigger in S32K

S32K ADC + DMA + PDB trigger

felix_niessen — Tue, 09 Apr 2019 07:37:16 GMT

Hi,

i same problem here, in chapter 44.3.1 (ref. manual 8, 06/2018) i would like to know the PDB trigger sources. it says
"Refer to chip configuration details for the actual PDB input trigger"

but i cant find it. in the attached excel files are only the trigmux trigger which dont fit into 4 bit.

thanks!

Re: S32K ADC + DMA + PDB trigger

felix_niessen — Mon, 15 Apr 2019 13:27:59 GMT

To explain it a bit more, i would like to have the ADC sample one channel continuous until i stop it. the samples should be stored by DMA.

The DMA part is working, but i need to have the ADC COCO triggering back the PDB so it starts the next conversion.

for now i can sample the four SC1 inputs but then i need to restart the PDB manual (DMA interrupt or Loop).

thanks!

Re: S32K ADC + DMA + PDB trigger

victorjimenez — Mon, 15 Apr 2019 21:47:31 GMT

Hello Felix,

In section 44.1.1.2 of the reference manual says: "On this device, the PDB trigger source selection is implemented through the TRGMUX module. For each PDB unit, there is only one trigger input from TRGMUX, but it supports different trigger sources. The internal trigger mux inside PDB is not used anymore."

So, from the Trigger input source select, the only option you have is 0000 Trigger-In 0 selected. All the other options are now reserved.

From the RM Figure 19-2, you can see that you have the following Trigger Source options: ADC0_SC1A[COCO] in30, ADC0_SC1B[COCO] in31, ADC1_SC1A[COCO]in32, and ADC1_SC1B[COCO] in33. For example, If you want to target module PDB0_trigger_in0 with ADC0_SC1A[COCO] then in the field SEL0 of the register TRGMUX PDB0 you need to put the 30.

Have a great day,
TIC

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Re: S32K ADC + DMA + PDB trigger

felix_niessen — Mon, 29 Apr 2019 15:22:17 GMT

Hi, yes this answers my question. Thanks! Will try it tomorrow.

Am i right that there is no direct way to have the adc trigger it self? Like a continous conversion of one channel?

Regards

Felix

Re: S32K ADC + DMA + PDB trigger

victorjimenez — Tue, 30 Apr 2019 17:14:56 GMT

Hello Felix,

You are right. For ADC trigger source options you only have the following signals ADC0_SC1A[COCO], ADC0_SC1B[COCO], ADC1_SC1A[COCO], and ADC1_SC1B[COCO].

Best regards,

Victor.