Overview
To drive an innovative IoT product to market, software is key. For products based on the versatile and efficient EFM32 MCU family, Silicon Labs delivers a comprehensive SDK to help ensure an optimal software development experience. The 32-bit MCU SDK provides all of the components needed, from basic register-access routines to high-level services, to fully leverage the capabilities of each EFM32 device.
The foundation of the 32-bit MCU SDK is a collection of drivers, software services, and other helpful components known as Gecko Platform. The wide-ranging capabilities of Gecko Platform allow it to fully bridge the gap between application code and the underlying hardware. The key components of Gecko Platform include the following:
EMLIB
Simple and effective, EMLIB is for developers who prefer to work close to hardware. It is a low-level library providing access to all EFM32 peripherals and core features. The EMLIB API is consistent across not only EFM32 devices, but Silicon Labs’ EFR32 wireless SoCs as well.
Drivers
The drivers delivered in Gecko Platform provide a higher level of abstraction than EMLIB. They are generally interrupt-based and, where applicable, leverage DMA. Most drivers offer synchronous and asynchronous APIs, in addition to making use of the energy saving features available on certain peripherals.
RTOS
Gecko Platform enables the development of both bare-metal and multi-task, RTOS-based projects. It incorporates the source code of two widely used, professional-grade RTOSes: FreeRTOS and Micrium OS. The platform’s various services can be easily configured for use with either of these RTOS options.
Services
Given the increasing complexity of IoT projects, successful application software development efforts require more than just a means of accessing hardware and peripherals. The services implemented by Gecko Platform distill important system-level functionality into intuitive API functions. Below is a summary of key services.
| Service | Benefit | |
|---|---|---|
| Command Line Interface | Enables rapid implementation of a fully customizable interface for accepting and processing user commands. | |
| Device Initialization | Streamlines development of startup code via simple APIs that combine important initialization operations. | |
| HFXO Manager | Eliminates the need to manually manage high-frequency oscillator startup failures. | |
| IO Stream | Allows implementation of user input and output capabilities without detailed knowledge of the underlying communication mechanisms. | |
| MPU RAM Execution Disable Utilities | Helps to protect against code-injection attacks. | |
| Power Manager | Centralizes power management using a single set of intuitive APIs. | |
| Secure Engine Manager | Enables the efficient, yet robust, implementation of vital security functionality. | |
| Sleep Timer | Leverages simple timer hardware to provide an incredibly flexible collection of time, date, and delay routines. | |
| System Initialization and Action Processing | Simplifies initialization and action processing by taking advantage of automatically generated code. | |
| Token Manager | Gives application code convenient access to non-volatile storage for important data like manufacturing IDs and channel numbers. |
Downloads
Download and Install Simplicity Studio
The Simplicity Studio IDE contains everything you’ll need to make your next 32-bit MCU project a success. The IDE will guide you through an installation perfectly suited to your device and application requirements. You’ll be able to leverage a range of helpful software examples that can be fully customized using a robust graphical configuration framework. To get started, choose your software package below.
GitHub
Silicon Labs wireless IoT SDKs and code examples are also available for download on GitHub.
VS Code IDE Support
In addition to the Simplicity Studio IDE, we also support VS Code that can be used in companion with all of our unique development tools.
Tech Docs
Gecko SDK Release Notes (4.5.0.0)
Latest Release - Q4/2025 (October 2025)
32-bit MCU Version 6.6.7.0
- Added support for new OPNs
- Upgrade compilers to GCC 12.2.1 and IAR 9.40.1
| Release | Date | Release Notes |
|---|---|---|
| 2025 | 2025/10 | Version 6.6.7.0  |
| 2025/02 | Version 6.6.6.0 |
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| 2025/01 | Version 6.4.7.0 |
|
| 2024 | 2024/10 | Version 6.6.5.0 |
| 2024/08 | Version 6.6.4.0 |
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| 2024/07 | Version 6.4.6.0 |
|
| 2024/05 | Version 6.6.3.0 |
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| 2024/04 | Version 6.6.2.0 |
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| 2024/03 | Version 6.5.3.0 |
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| 2024/02 | Version 6.6.1.0 |
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| 2024/01 | Version 6.4.5.0 |
Gecko Platform Version 4.4.7.0
- Peripherals
- New API names introduced for low-level drivers (with compatibility layer for old names)
- New API names introduced for low-level drivers (with compatibility layer for old names)
- Services
- APIs for accessing value of tokens added to Token Manager
- APIs for accessing value of tokens added to Token Manager
- CPC
- NVM3 module, enabling Host access to Secondary device's non-volatile memory, released at production quality
- CPC Primary, for use with MCU Hosts, released at Experimental quality
- Numerous optimizations and performance improvements made
- Security
- Mbed TLS upgraded (to version 3.5.0)
- RAIL
- Several new features added for EFR32xG25 devices, including a new component for selecting modulations supported by the software modem
- Support added for several new PHYs, including Sidewalk PHYs on EFR32xG23 and EFR32xG28
- Other Components
- Compilers upgraded (to GCC 12.2.1 and IAR 9.40.1)
| Release | Date | Release Notes |
|---|---|---|
| 2025 | 2025/10 | Version 4.4.7.0 |
| 2025/02 | Version 4.4.6.0 |
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| 2025/01 | Version 4.2.7.0 |
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| 2024 | 2024/10 | Version 4.4.5.0 |
| 2024/08 | Version 4.4.4.0 |
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| 2024/07 | Version 4.2.6.0 |
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| 2024/05 | Version 4.4.3.0 |
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| 2024/04 | Version 4.4.2.0 |
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| 2024/03 | Version 4.3.3.0 |
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| 2024/02 | Version 4.4.1.0 |
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| 2024/01 | Version 4.2.5.0 |
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