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cpu/efm32/doc.md

2026.07-devel3.3 KB
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@defgroup cpu_efm32 Silicon Labs EFM32/EFR32/EZR32 @ingroup cpu @brief Silicon Labs's EFM32/EFR32/EZR32 MCUs implementation

This module contains all code and definitions for the Silicon Labs EFM32/EFR32/EZR32 MCUs. It uses the Gecko SDK (vendor library) for the peripheral drivers.

Supported Peripherals

The following peripherals are supported (depends on microcontroller):

  • ADC
  • CPUID
  • DAC
  • Flash page
  • GPIO
  • HW RNG
  • I2C
  • Power Management
  • PWM
  • RTC
  • RTT
  • SPI
  • Timer
  • UART (including low-power)

Clock Configuration

By default the microcontroller will run on the internal RC-oscillator. If an external crystal is available, you can configure it to use by setting CLOCK_HF=cmuSelect_HFXO. The same applies for CLOCK_LFA, CLOCK_LFB and CLOCK_LFE using cmuSelect_LFXO.

If the internal RC-oscillator is not used, it will be disabled.

Refer to the reference manual of the specific microcontroller for the specifics.

EMU and CMU Configuration

The Energy Management Unit (EMU) and Clock Management Unit (CMU) are initialized using default values provided by the Gecko SDK. You can override any of the following defaults to use other values:

  • CMU_HFXOINIT
  • CMU_LFXOINIT
  • EMU_DCDCINIT
  • EMU_EM23INIT
  • EMU_EM4INIT

Refer to the Gecko SDK for more information about these values.

Low-power Configuration

The EFM32/EFR32/EZR32 MCUs have support for low-power peripherals. Support is enabled by default, but can be disabled if not used.

  • Setting EFM32_LEUART_ENABLED=0 will disable support for the LEUART in the UART driver peripheral and save approximately 400 bytes. Refer to cpu/efm32/efm32-features.mk for more options.

@defgroup cpu_efm32gg Silicon Labs EFM32GG family @ingroup cpu_efm32 @brief Silicon Labs's EFM32GG MCUs family implementation

@defgroup cpu_efm32hg Silicon Labs EFM32HG family @ingroup cpu_efm32 @brief Silicon Labs's EFM32HG MCUs family implementation

@defgroup cpu_efm32lg Silicon Labs EFM32LG family @ingroup cpu_efm32 @brief Silicon Labs's EFM32LG MCUs family implementation

@defgroup cpu_efm32pg1b Silicon Labs EFM32PG1B family @ingroup cpu_efm32 @brief Silicon Labs's EFM32PG1B MCUs family implementation

@defgroup cpu_efm32pg12b Silicon Labs EFM32PG12B family @ingroup cpu_efm32 @brief Silicon Labs's EFM32PG12B MCUs family implementation

@defgroup cpu_efm32zg Silicon Labs EFM32ZG family @ingroup cpu_efm32 @brief Silicon Labs's EFM32ZG MCUs family implementation

@defgroup cpu_efr32mg1b Silicon Labs EFR32MG1P family @ingroup cpu_efm32 @brief Silicon Labs's EFR32MG1B MCUs family implementation

@defgroup cpu_efr32mg1p Silicon Labs EFR32MG1P family @ingroup cpu_efm32 @brief Silicon Labs's EFR32MG1P MCUs family implementation

@defgroup cpu_efr32mg12p Silicon Labs EFR32MG12P family @ingroup cpu_efm32 @brief Silicon Labs's EFR32MG12P MCUs family implementation

@defgroup cpu_ezr32wg Silicon Labs EZR32WG family @ingroup cpu_efm32 @brief Silicon Labs's EZR32WG MCUs family implementation