Bonjour Antoine,normally my code starts with RCC->APBENR2 |=... => the SYSSCFG reset bit = 0Now I can write to CSR and when I read it back its OK.VREF+Pin is connected via a ferrit with VDD/VDDA (3.3V) as long as HIZ = 1 (Default). Only if I set HIZ ...

Hi Jan,first of all thank you for your support. I actually forgot to set RCC_APBENR2.SYSCFGEN = 1.If I now read VREFBUF.CSR there are the correct values for VRS, HIW and ENVR.I thought it would work now but unfortunately not. VRR still remains at 0 a...

Hi Jan,yes I tried this too. Here is the code:   VREFBUF->CSR = 0x000000001;   // ...00000001 VRS=0, HIZ=0, ENVR=1 => VREF, VREF+Pin = 2.048V   //VREFBUF->CSR = 0x000000005;   // ...00000101 VRS=1, HIZ=0, ENVR=1 => VREF, VREF+Pin = 2.500VBut in this ...

Hi Jan,in this case VRR should go high after settling, but it stays low for ever? Here is the code:VREFBUF->CSR = 0x000000003;   // ...00000011 VRS=0, HIZ=1, ENVR=1 => VREF = 2.048Vwhile ((VREFBUF->CSR & 0x00000008) == 0);      // Wait until VRR = 1 ...