Error in reading ADC->CDR under Dual ADC and regular simultaneous mode

[JLee.2254]

I am using ADC1 and ADC2 of STM32F446RE, which are operated under the following conditions;

• Dual ADC mode
• Regular Simultaneous mode​
• External trigger

I can correctly read the converted values through ADC1->DR and ADC2->DR.

However, I can not read the correct converted values through ADC->CDR.

(Each converted value is always zero...)

According to the manual, the contents of ADC-CDR contains the data of ADC1->DR and ADC2->DR in dual ADC mode.

What key points am I missing? or ...

[waclawek.jan]

This appears to work only is ADC_CCR.DMA is nonzero. I know, this is not documented. Also, ADC_CSR.EOCx bits are cleared by the CDR read - this is understandable, but not documented either.

JW

PS. Change your username to a normal nick.

@Vincent Onde​ @Imen DAHMEN​