DocID025832 Rev 2
STM32F042xx
Pinouts and pin descriptions
40
Table 13. STM32F042x pin definitions
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
1
-
-
-
-
-
VBAT
S
-
-
Backup power supply
2
A6
-
-
-
-
PC13
I/O
TC
(1)
(2)
-
WKUP2,
RTC_TAMP1,
RTC_TS,
RTC_OUT
3
B6
-
-
-
-
PC14-
OSC32_IN
(PC14)
I/O TC
-
OSC32_IN
4
C6
-
-
-
-
PC15-
OSC32_OUT
(PC15)
I/O TC
-
OSC32_OUT
5
B5
2
2
2
2
PF0-OSC_IN
(PF0)
I/O
FTf
-
CRS_ SYNC
I2C1_SDA
OSC_IN
6
C5
3
3
3
3
PF1-OSC_OUT
(PF1)
I/O
FTf
-
I2C1_SCL
OSC_OUT
7
D5
4
4
4
4
NRST
I/O
RST
-
Device reset input / internal reset output
(active low)
8
D6
32
0
16
15
VSSA
S
-
Analog ground
9
E5
5
5
5
5
VDDA
S
-
Analog power supply
10
F6
6
6
6
6
PA0
I/O
TTa
-
USART2_CTS,
TIM2_CH1_ETR,
TSC_G1_IO1
RTC_
TAMP2,
WKUP1,
ADC_IN0,
11
D4
7
7
7
7
PA1
I/O
TTa
-
USART2_RTS,
TIM2_CH2,
TSC_G1_IO2,
EVENTOUT
ADC_IN1
12
E4
8
8
8
8
PA2
I/O
TTa
-
USART2_TX,
TIM2_CH3,
TSC_G1_IO3
ADC_IN2,
WKUP4
13
F5
9
9
9
9
PA3
I/O
TTa
-
USART2_RX,
TIM2_CH4,
TSC_G1_IO4
ADC_IN3