S32K148 adc not working

guochuan — Fri, 14 Apr 2023 07:26:18 GMT

Our project uses S32K148 ADC0 and ADC1, and each ADC is configured with 8 channels. The test found that the last three channels could not obtain data.

回复： S32K148 adc not working

guochuan — Fri, 14 Apr 2023 13:38:14 GMT

HI NXP team

Our project uses S32K148 ADC0 and ADC1, and each ADC is configured with 11 channels. The test found that the last three channels could not obtain data.

Re: S32K148 adc not working

Nhi_Nguyen — Tue, 25 Apr 2023 07:22:04 GMT

Hi guochuan,

I think the problem can come from this parameter is so small to convert data on all channels. So, you can try to adjust it.

This is its description

For example:

ADC's clock frequency is 40 MHz and prescaler value for frequency is 1.

PDB's clock frequency is 80MHz get from SYS_CLK

Follow to above expression for 1 ADC's channel: "ADC TOTAL CONVERSION TIME = Sample Phase Time (set by SMPLTS+1) + Hold Phase (1 ADC Cycle) + Compare Phase Time (8-bit Mode=20 ADC Cycles, 10-bit Mode=24 ADC Cycles,
12-bit Mode=28 ADC Cycles) + Single or First continuous time adder (5 ADC cycles + 5 bus clock cycles)."

SMPLTS:

I used 12 bit Mode.

In my case, ADC cycle = Bus cycle.

ADC TOTAL CONVERSION TIME = (255 + 1) + 1 + 28 + 10 = 295.

I have this parameter:

So, I have: ADC TOTAL CONVERSION TIME = 295 * 8 * 8 (channels) = 18880 (cycles)

This parameter Adc Delay Next PDB (0 -> 65535) have to ensure enough time to convert all pre-triggers in channel 0 and this value will be written as counter of PDB. So, we need to convert to PDB's cycles before write it into the register.

(18880/ 40 * 80 = 37760)

Adc Delay Next PDB (0 -> 65535) have to configure bigger than 37760.

Best regards,

Nhi

S32K中的主题 Re: S32K148 adc not working

S32K148 adc not working

回复： S32K148 adc not working

Re: S32K148 adc not working