Pin descriptions STM32L151x 6/8/B, STM32L152x6/8/B 36/131 DocID17659 Rev 9 Table 8. STM32L15xxx pin definitions Pins Pin name Pin type (1) I/O structure Main function (2) (after reset) Alternate functions LQFP100 LQFP64 TFBGA64 UFBGA100 LQFP48 or UFQFPN48 1 - - B2 - PE2 I/O FT PE2 TRACECLK/LCD_SEG38/TIM3_ETR 2 - - A1 - PE3 I/O FT PE3 TRACED0/LCD_SEG39/TIM3_CH1 3 - - B1 - PE4 I/O FT PE4 TRACED1/TIM3_CH2 4 - - C2 - PE5 I/O FT PE5 TRACED2/TIM9_CH1 5 - - D2 - PE6-WKUP3 I/O FT PE6 TRACED3/WKUP3/TIM9_CH2 6 1 B2 E2 1 VLCD S VLCD - 7 2 A2 C1 2 PC13-WKUP2 I/O FT PC13 RTC_TAMP1/RTC_TS/RTC_OUT/WKUP2 8 3 A1 D1 3 PC14-OSC32_IN I/O TC PC14 OSC32_IN 9 4 B1 E1 4 PC15-OSC32_OUT I/O TC PC15 OSC32_OUT 10 - - F2 - VSS_5 S - VSS_5 - 11 - - G2 - VDD_5 S - VDD_5 - 12 5 C1 F1 5 PH0-OSC_IN I/O TC PH0 OSC_IN 13 6 D1 G1 6 PH1-OSC_OUT I/O TC PH1 OSC_OUT 14 7 E1 H2 7 NRST I/O RST NRST - 15 8 E3 H1 - PC0 I/O FT PC0 ADC_IN10/LCD_SEG18/COMP1_INP 16 9 E2 J2 - PC1 I/O FT PC1 ADC_IN11/LCD_SEG19/COMP1_INP 17 10 F2 J3 - PC2 I/O FT PC2 ADC_IN12/LCD_SEG20/COMP1_INP 18 11 - K2 - PC3 I/O TC PC3 ADC_IN13/LCD_SEG21/COMP1_INP 19 12 F1 J1 8 VSSA S- VSSA - 20 - - K1 - VREF- S - VREF- - 21 - G1 L1 - VREF+ S - VREF+ - 22 13 H1 M1 9 VDDA S - VDDA - 23 14 G2 L2 10 PA0-WKUP1 I/O FT PA0 WKUP1/USART2_CTS/ADC_IN0/TIM2_CH1_ETR/COMP1_INP 24 15 H2 M2 11 PA1 I/O FT PA1 USART2_RTS/ADC_IN1/TIM2_CH2/LCD_SEG0/COMP1_INP 25 16 F3 K3 12 PA2 I/O FT PA2 USART2_TX/ADC_IN2/TIM2_CH3/TIM9_CH1/LCD_SEG1/COMP1_INP 26 17 G3 L3 13 PA3 I/O TC PA3 USART2_RX/ADC_IN3/TIM2_CH4/TIM9_CH2/LCD_SEG2/COMP1_INP 27 18 C2 E3 - VSS_4 S - VSS_4 - 28 19 D2 H3 - VDD_4 S - VDD_4 - 29 20 H3 M3 14 PA4 I/O TC PA4 SPI1_NSS/USART2_CK/ADC_IN4/DAC_OUT1/COMP1_INP 30 21 F4 K4 15 PA5 I/O TC PA5 SPI1_SCK/ADC_IN5/DAC_OUT2/TIM2_CH1_ETR/COMP1_INP 31 22 G4 L4 16 PA6 I/O FT PA6 SPI1_MISO/ADC_IN6/TIM3_CH1/LCD_SEG3/TIM10_CH1/COMP1_INP 32 23 H4 M4 17 PA7 I/O FT PA7 SPI1_MOSI/ADC_IN7/TIM3_CH2/LCD_SEG4/TIM11_CH1/COMP1_INP 33 24 H5 K5 - PC4 I/O FT PC4 ADC_IN14/LCD_SEG22/COMP1_INP 34 25 H6 L5 - PC5 I/O FT PC5 ADC_IN15/LCD_SEG23/COMP1_INP 35 26 F5 M5 18 PB0 I/O TC PB0 ADC_IN8/TIM3_CH3/LCD_SEG5/COMP1_INP/VREF_OUT 36 27 G5 M6 19 PB1 I/O FT PB1 ADC_IN9/TIM3_CH4/LCD_SEG6/COMP1_INP/VREF_OUT 37 28 G6 L6 20 PB2 I/O FT PB2/BOOT1 - 38 - - M7 - PE7 I/O TC PE7 ADC_IN22/COMP1_INP 39 - - L7 - PE8 I/O TC PE8 ADC_IN23/COMP1_INP 40 - - M8 - PE9 I/O TC PE9 ADC_IN24/TIM2_CH1_ETR/COMP1_INP 41 - - L8 - PE10 I/O TC PE10 ADC_IN25/TIM2_CH2/COMP1_INP 42 - - M9 - PE11 I/O FT PE11 TIM2_CH3 43 - - L9 - PE12 I/O FT PE12 TIM2_CH4/SPI1_NSS 44 - - M10 - PE13 I/O FT PE13 SPI1_SCK 45 - - M11 - PE14 I/O FT PE14 SPI1_MISO 46 - - M12 - PE15 I/O FT PE15 SPI1_MOSI 47 29 G7 L10 21 PB10 I/O FT PB10 I2C2_SCL/USART3_TX/TIM2_CH3/LCD_SEG10 48 30 H7 L11 22 PB11 I/O FT PB11 I2C2_SDA/USART3_RX/TIM2_CH4/LCD_SEG11 49 31 D6 F12 23 VSS_1 S - VSS_1 - 50 32 E6 G12 24 VDD_1 S - VDD_1 - 51 33 H8 L12 25 PB12 I/O FT PB12 SPI2_NSS/I2C2_SMBA/USART3_CK/LCD_SEG12/ADC_IN18/COMP1_INP/TIM10_CH1 52 34 G8 K12 26 PB13 I/O FT PB13 SPI2_SCK/USART3_CTS/LCD_SEG13/ADC_IN19/COMP1_INP/TIM9_CH1 53 35 F8 K11 27 PB14 I/O FT PB14 SPI2_MISO/USART3_RTS/LCD_SEG14/ADC_IN20/COMP1_INP/TIM9_CH2 54 36 F7 K10 28 PB15 I/O FT PB15 SPI2_MOSI/LCD_SEG15/ADC_IN21/COMP1_INP/TIM11_CH1/RTC_REFIN 55 - - K9 - PD8 I/O FT PD8 USART3_TX/LCD_SEG28 56 - - K8 - PD9 I/O FT PD9 USART3_RX/LCD_SEG29 57 - - J12 - PD10 I/O FT PD10 USART3_CK/LCD_SEG30 58 - - J11 - PD11 I/O FT PD11 USART3_CTS/LCD_SEG31 59 - - J10 - PD12 I/O FT PD12 TIM4_CH1/USART3_RTS/LCD_SEG32 60 - - H12 - PD13 I/O FT PD13 TIM4_CH2/LCD_SEG33 61 - - H11 - PD14 I/O FT PD14 TIM4_CH3/LCD_SEG34 62 - - H10 - PD15 I/O FT PD15 TIM4_CH4/LCD_SEG35 63 37 F6 E12 - PC6 I/O FT PC6 TIM3_CH1/LCD_SEG24 64 38 E7 E11 - PC7 I/O FT PC7 TIM3_CH2/LCD_SEG25 65 39 E8 E10 - PC8 I/O FT PC8 TIM3_CH3/LCD_SEG26 66 40 D8 D12 - PC9 I/O FT PC9 TIM3_CH4/LCD_SEG27 67 41 D7 D11 29 PA8 I/O FT PA8 USART1_CK/MCO/LCD_COM0 68 42 C7 D10 30 PA9 I/O FT PA9 USART1_TX/LCD_COM1 69 43 C6 C12 31 PA10 I/O FT PA10 USART1_RX/LCD_COM2 70 44 C8 B12 32 PA11 I/O FT PA11 USART1_CTS/USB_DM/SPI1_MISO 71 45 B8 A12 33 PA12 I/O FT PA12 USART1_RTS/USB_DP/SPI1_MOSI 72 46 A8 A11 34 PA13 I/O FT JTMS/SWDAT - 73 - - C11 - PH2 I/O FT PH2 - 74 47 D5 F11 35 VSS_2 S - VSS_2 - 75 48 E5 G11 36 VDD_2 S - VDD_2 - 76 49 A7 A10 37 PA14 I/O FT JTCK/SWCLK - 77 50 A6 A9 38 PA15 I/O FT JTDI TIM2_CH1_ETR/PA15/SPI1_NSS/LCD_SEG17 78 51 B7 B11 - PC10 I/O FT PC10 USART3_TX/LCD_SEG28/LCD_SEG40/LCD_COM4 79 52 B6 C10 - PC11 I/O FT PC11 USART3_RX/LCD_SEG29/LCD_SEG41/LCD_COM5 80 53 C5 B10 - PC12 I/O FT PC12 USART3_CK/LCD_SEG30/LCD_SEG42/LCD_COM6 81 - - C9 - PD0 I/O FT PD0 SPI2_NSS/TIM9_CH1 82 - - B9 - PD1 I/O FT PD1 SPI2_SCK 83 54 B5 C8 - PD2 I/O FT PD2 TIM3_ETR/LCD_SEG31/LCD_SEG43/LCD_COM7 84 - - B8 - PD3 I/O FT PD3 USART2_CTS/SPI2_MISO 85 - - B7 - PD4 I/O FT PD4 USART2_RTS/SPI2_MOSI 86 - - A6 - PD5 I/O FT PD5 USART2_TX 87 - - B6 - PD6 I/O FT PD6 USART2_RX 88 - - A5 - PD7 I/O FT PD7 USART2_CK/TIM9_CH2 89 55 A5 A8 39 PB3 I/O FT JTDO TIM2_CH2/PB3/SPI1_SCK/COMP2_INM/LCD_SEG7 90 56 A4 A7 40 PB4 I/O FT NJTRST TIM3_CH1/PB4/SPI1_MISO/COMP2_INP/LCD_SEG8 91 57 C4 C5 41 PB5 I/O FT PB5 I2C1_SMBA/TIM3_CH2/SPI1_MOSI/COMP2_INP/LCD_SEG9 92 58 D3 B5 42 PB6 I/O FT PB6 I2C1_SCL/TIM4_CH1/USART1_TX 93 59 C3 B4 43 PB7 I/O FT PB7 I2C1_SDA/TIM4_CH2/USART1_RX/PVD_IN 94 60 B4 A4 44 BOOT0 I B BOOT0 - 95 61 B3 A3 45 PB8 I/O FT PB8 TIM4_CH3/I2C1_SCL/LCD_SEG16/TIM10_CH1 96 62 A3 B3 46 PB9 I/O FT PB9 TIM4_CH4/I2C1_SDA/LCD_COM3/TIM11_CH1 97 - - C3 - PE0 I/O FT PE0 TIM4_ETR/LCD_SEG36/TIM10_CH1 98 - - A2 - PE1 I/O FT PE1 LCD_SEG37/TIM11_CH1 99 63 D4 D3 47 VSS_3 S - VSS_3 - 100 64 E4 C4 48 VDD_3 S - VDD_3 -