Name Abbreviation Definition
Pin name Unless otherwise specified in brackets below the pin name, the pin function during and
after reset is the same as the actual pin name
Pin type
S Supply pin
I Input only pin
I/O Input / output pin
I/O structure
FT 5 V tolerant I/O
FTf 5 V tolerant I/O, FM+ capable
TTa 3.3 V tolerant I/O directly connected to ADC
TC Standard 3.3 V I/O
B Dedicated BOOT0 pin
RST Bidirectional reset pin with embedded weak pull-up resistor
Notes Unless otherwise specified by a note, all I/Os are set as floating inputs during and after
reset.
Pin
functions
Alternate
functions Functions selected through GPIOx_AFR registers
Additional
functions Functions directly selected/enabled through peripheral registers
Pin name Unless otherwise specified in brackets below the pin name, the pin function during and
after reset is the same as the actual pin name
Pin type
S Supply pin
I Input only pin
I/O Input / output pin
I/O structure
FT 5 V tolerant I/O
FTf 5 V tolerant I/O, FM+ capable
TTa 3.3 V tolerant I/O directly connected to ADC
TC Standard 3.3 V I/O
B Dedicated BOOT0 pin
RST Bidirectional reset pin with embedded weak pull-up resistor
Notes Unless otherwise specified by a note, all I/Os are set as floating inputs during and after
reset.
Pin
functions
Alternate
functions Functions selected through GPIOx_AFR registers
Additional
functions Functions directly selected/enabled through peripheral registers