DocID025832 Rev 2
STM32F042xx
Pinouts and pin descriptions
40
46
-
-
-
-
-
PB9
I/O
FTf
-
SPI2_NSS,
I2C1_SDA, IR_OUT,
TIM17_CH1,
EVENTOUT,
CAN_TX
-
47
-
32
0
-
-
VSS
S
-
-
Ground
48
A5
1
1
-
-
VDD
S
-
-
Digital power supply
1. PC13, PC14 and PC15 are supplied through the power switch. Since the switch only sinks a limited amount of current
(3
mA), the use of GPIOs PC13 to PC15 in output mode is limited:
- The speed should not exceed 2
MHz with a maximum load of 30
pF.
- These GPIOs must not be used as current sources (e.g. to drive an LED).
2. After the first RTC domain power-up, PC13, PC14 and PC15 operate as GPIOs. Their function then depends on the
content of the RTC registers which are not reset by the system reset. For details on how to manage these GPIOs, refer to
the RTC domain and RTC register descriptions in the reference manual.
3. PA8, PA9, PA10, PA11, PA12, PA13, PA14 and PA15 I/Os are supplied by VDDIO2.
4. Pin pair PA11/12 can be remapped instead of pin pair PA9/10 using SYSCFG_CFGR1 register.
5. After reset, these pins are configured as SWDIO and SWCLK alternate functions, and the internal pull-up on the SWDIO
pin and the internal pull-down on the SWCLK pin are activated.
Table 13. STM32F042x pin definitions (continued)
Pin numbers
Pin name
(function after
reset)
Pin
type
I/O structure
Notes
Pin functions
LQFP48/UFQFPN48
WLCSP36
LQFP32
UFQFPN32
UFQFPN28
TSSPOP20
Alternate function
Additional
functions