1. Documentation conventions
1.1 General information
The STM32L41xxx/42xxx/43xxx/44xxx/45xxx/46xxx devices have an Arm ®(a) Cortex ® -M4 core.
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1.2 List of abbreviations for registers
The following abbreviations (b) are used in register descriptions:
| read/write (rw) | Software can read and write to this bit. |
| read-only (r) | Software can only read this bit. |
| write-only (w) | Software can only write to this bit. Reading this bit returns the reset value. |
| read/clear write0 (rc_w0) | Software can read as well as clear this bit by writing 0. Writing 1 has no effect on the bit value. |
| read/clear write1 (rc_w1) | Software can read as well as clear this bit by writing 1. Writing 0 has no effect on the bit value. |
| read/clear write (rc_w) | Software can read as well as clear this bit by writing to the register. The value written to this bit is not important. |
| read/clear by read (rc_r) | Software can read this bit. Reading this bit automatically clears it to 0. Writing this bit has no effect on the bit value. |
| read/set by read (rs_r) | Software can read this bit. Reading this bit automatically sets it to 1. Writing this bit has no effect on the bit value. |
| read/set (rs) | Software can read as well as set this bit. Writing 0 has no effect on the bit value. |
| read/write once (rwo) | Software can only write once to this bit and can also read it at any time. Only a reset can return the bit to its reset value. |
| toggle (t) | The software can toggle this bit by writing 1. Writing 0 has no effect. |
| read-only write trigger (rt_w1) | Software can read this bit. Writing 1 triggers an event but has no effect on the bit value. |
| Reserved (Res.) | Reserved bit, must be kept at reset value. |
a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.
b. This is an exhaustive list of all abbreviations applicable to STMicroelectronics microcontrollers, some of them may not be used in the current document.
1.3 Glossary
This section gives a brief definition of acronyms and abbreviations used in this document:
- • Word : data of 32-bit length.
- • Half-word : data of 16-bit length.
- • Byte : data of 8-bit length.
- • IAP (in-application programming) : IAP is the ability to re-program the flash memory of a microcontroller while the user program is running.
- • ICP (in-circuit programming) : ICP is the ability to program the flash memory of a microcontroller using the JTAG protocol, the SWD protocol or the bootloader while the device is mounted on the user application board.
- • Option bytes : device configuration bits stored in the flash memory.
- • OBL : option byte loader.
- • AHB : advanced high-performance bus.
- • APB : advanced peripheral bus.
1.4 Availability of peripherals
For availability of peripherals and their number across all devices, refer to the particular device datasheet.
1.5 Product specific features
Table 1. Product specific features
| Feature | STM32 L412xx | STM32 L422xx | STM32 L431xx | STM32 L432xx | STM32 L433xx | STM32 L442xx | STM32 L443xx | STM32 L451xx | STM32 L452xx | STM32 L462xx |
|---|---|---|---|---|---|---|---|---|---|---|
| ADC | ADC1 ADC2 | ADC1 ADC2 | ADC1 - | ADC1 - | ADC1 - | ADC1 - | ADC1 - | ADC1 - | ADC1 - | ADC1 - |
| DAC | - | - | DAC1 | DAC1 | DAC1 | DAC1 | DAC1 | DAC1 | DAC1 | DAC1 |
| COMP | COMP1 - | COMP1 - | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 | COMP1 COMP2 |
| DFSDM | - | - | - | - | - | - | - | DFSDM 1 | DFSDM 1 | DFSDM 1 |
| LCD | - | - | - | - | LCD | - | LCD | - | - | - |
| AES | - | AES | - | - | - | AES | AES | - | - | AES |
| TIM | TIM1 TIM2 - TIM6 - TIM15 TIM16 | TIM1 TIM2 - TIM6 - TIM15 TIM16 | TIM1 TIM2 - TIM6 TIM7 TIM15 TIM16 | TIM1 TIM2 - TIM6 TIM7 TIM15 TIM16 | TIM1 TIM2 - TIM6 TIM7 TIM15 TIM16 | TIM1 TIM2 - TIM6 TIM7 TIM15 TIM16 | TIM1 TIM2 - TIM6 TIM7 TIM15 TIM16 | TIM1 TIM2 TIM3 TIM6 - TIM15 TIM16 | TIM1 TIM2 TIM3 TIM6 - TIM15 TIM16 | TIM1 TIM2 TIM3 TIM6 - TIM15 TIM16 |
Table 1. Product specific features (continued)
| Feature | STM32 L412xx | STM32 L422xx | STM32 L431xx | STM32 L432xx | STM32 L433xx | STM32 L442xx | STM32 L443xx | STM32 L451xx | STM32 L452xx | STM32 L462xx |
|---|---|---|---|---|---|---|---|---|---|---|
| I2C | I2C1 I2C2 I2C3 - | I2C1 I2C2 I2C3 - | I2C1 I2C2 I2C3 - | I2C1 - I2C3 - | I2C1 I2C2 I2C3 - | I2C1 - I2C3 - | I2C1 I2C2 I2C3 - | I2C1 I2C2 I2C3 I2C4 | I2C1 I2C2 I2C3 I2C4 | I2C1 I2C2 I2C3 I2C4 |
| USART | USART1 USART2 USART3 - | USART1 USART2 USART3 - | USART1 USART2 USART3 - | USART1 USART2 - - | USART1 USART2 USART3 - | USART1 USART2 - - | USART1 USART2 USART3 - | USART1 USART2 USART3 UART4 | USART1 USART2 USART3 UART4 | USART1 USART2 USART3 UART4 |
| LPUART | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 | LPUART 1 |
| SPI | SPI1 SPI2 - | SPI1 SPI2 - | SPI1 SPI2 SPI3 | SPI1 - SPI3 | SPI1 SPI2 SPI3 | SPI1 - SPI3 | SPI1 SPI2 SPI3 | SPI1 SPI2 SPI3 | SPI1 SPI2 SPI3 | SPI1 SPI2 SPI3 |
| SAI | - | - | SAI | SAI | SAI | SAI | SAI | SAI | SAI | SAI |
| SWPMI | - | - | SWPMI1 | SWPMI1 | SWPMI1 | SWPMI1 | SWPMI1 | - | - | - |
| SDMMC | - | - | SDMMC | - | SDMMC | - | SDMMC | SDMMC | SDMMC | SDMMC |
| USB | USB FS | USB FS | - | USB FS | USB FS | USB FS | USB FS | - | USB FS | USB FS |
| CAN1 | - | - | CAN1 | CAN1 | CAN1 | CAN1 | CAN1 | CAN1 | CAN1 | CAN1 |