My apologies for unable to find "Alternate Function Table" for GPIOC port which is similar to those on page 37 & 38 of the datasheet DocID022265 Rev 7. The MCU is STM32F051. Someone can help? Best Regards!

[waclawek.jan]

Pins of Port C on 'F51 (and 'F030x8) have zero or maximum one AF, so I guess GPIOC doesn't have AFR at all.

JW