STM32G4 ADC12_Common Register cannot be written

[LLOLO.1]

Hi! I am trying to set ADC pre-scaler of my STM32G431KB however no matter what I do it never changes from 0x0.

I can setup ADC1 register without a problem but when it comes to ADC12_Common register nothing seems to be configurable.

Below there is my ADC configuration code.

//-------------ADC Configuration-------------//
	ADC1->CR &= ~(ADC_CR_ADEN); //Disable ADC
	ADC12_COMMON->CCR |= (0b00<<ADC_CCR_CKMODE_Pos); //Select ADC clock Source in Peripheral
	ADC12_COMMON->CCR |= (0b1000<<ADC_CCR_PRESC_Pos); //ADC Clock divided by 32
 
	ADC1->CR &= ~(ADC_CR_DEEPPWD); //Disable ADC Deep-Power-Down mode
	ADC1->CR |= ADC_CR_ADVREGEN; //Enable ADC Voltage Regulator
	DummyDelay(10000); //Delay for ADC Voltage regulator settling
 
	ADC1->CFGR |= ADC_CFGR_CONT; //ADC continuous mode
	ADC1->CFGR &= ~(ADC_CFGR_RES); //12-bit ADC
	ADC1->SQR1 |= (0b0000 << ADC_SQR1_L_Pos) | (1 << ADC_SQR1_SQ1_Pos); // Only 1 conversion for ADC channel 1
	ADC1->DIFSEL &= ~(ADC_DIFSEL_DIFSEL_0); //Single Ended Input
 
	ADC1->CFGR2 |= (0b0001 << ADC_CFGR2_OVSS_Pos); //Over-sampling mode 1 bit shift
	ADC1->CFGR2 |= (0b001 << ADC_CFGR2_OVSR_Pos); //Over-sampling ratio x4
	ADC1->CFGR2 |= ADC_CFGR2_ROVSE; //Enable Over-sampling
 
	ADC1->CFGR |= ADC_CFGR_DMAEN | ADC_CFGR_DMACFG; //Enable DMA for ADC and DMA in Circular Mode
 
	ADC1->CR &= ~(ADC_CR_ADCALDIF); //Single Ended Mode Calibration
	ADC1->CR |= ADC_CR_ADCAL; //Start Calibration
	while(ADC1->CR & ADC_CR_ADCAL); //Wait Until Calibration Complete
 
	ADC1->ISR |= ADC_ISR_ADRDY; //Clear ADRDY Flag
	ADC1->CR |= ADC_CR_ADEN; //Enable ADC
	while(!(ADC1->ISR & ADC_ISR_ADRDY)); //Wait Until ADC Enables

Can someone tell me what I am doing wrong in line 3 and 4 of above code?

[Bassett.David]

Hello,

Beware the .svd file for the STM32G4 has the wrong address for ADC12_Common (and ADC5). If you're trying to read/write them from a debugger, it will reference to the wrong address. I've mentioned this previously, but ST has not updated...

Good luck!

Regards,

Dave

[Imen.D]

Hello,

Thank you for highlighting this.

Please find attached the new svd file for STM32G431 with the fix.

 <name>ADC12_Common</name>
 <description>Analog-to-Digital Converter</description>
 <groupName>ADC</groupName>
 <baseAddress>0x50000300</baseAddress> 

The correction (for all the G4 devices) is implemented internally and will be available in the ST web page.

Best Regards,

Imen

[JAlca]

Hi!,

I think the STM32F303 has the same problem.

[LLOLO.1]

Thank you! You are right.

[LLOLO.1]

ADC12_COMMON->CCR |= (0b00<<ADC_CCR_CKMODE_Pos); //Select ADC clock Source in Peripheral

ADC12_COMMON->CCR |= (0b1000<<ADC_CCR_PRESC_Pos); //ADC Clock divided by 32

So these lines are correct right? The only issue is that I cannot see it in debugger right?

[waclawek.jan]

I don't know what debugger are you using, but you should be able to observe content on absolute addresses.

JW