STM32U031 contains wrong value under VREFINT_CAL_ADDR

[mmk]

My STM32U031R8T6U (CPU: UID=0x20353953_39365013_0030007C Lot#=59S96P Wafer#=19 X=48 Y=124 FLASH=64KB) has 0xFFFF under VREFINT_CAL_ADDR - the Vrefint calibration data are absent.

C code:

printf("\r\n *VREFINT_CAL_ADDR=%u", *VREFINT_CAL_ADDR);

Output:

*VREFINT_CAL_ADDR=65535

This issue seems to be similar to the one described in:

https://community.st.com/t5/stm32-mcus-products/stm32u073cc-vrefint-calibration-data-missing-value-wrong/m-p/716948#M259968

but hasn't been mentioned in the STM32U031 Errata Sheets.

[Imen.D · Accepted solution]

Hello @mmk and welcome to the Community, 

Our team is very aware of this issue and the STM32U031 Errata Sheet "ES0603" will be updated in the coming releases to include the errata.

An internal ticket number: 183723 is already submitted in order to fix such issue.

Thank you for your contribution.

(PS: ticket number 183723 is an internal tracking number and is not accessible or usable by customers).

[Andrew Neil]

Same issue:

https://community.st.com/t5/stm32-mcus-boards-and-hardware/reference-voltage-always-reads-as-0xffff/td-p/780887