Simplicity SDK Platform Version 5.2.1 (July 21, 2025) - Release Notes#

Simplicity SDK Version 2025.6.1

The Platform provides infrastructure support for applications developed with higher-level protocols, and it provides an interface with the underlying hardware.

Click here for earlier releases.

Release Summary#

Release Item	Version	Release Date	Release Notes	Key Features	API Changes	Bug Fixes	Chip Enablement
Platform MCU	5.2.1	July 21, 2025	Release Notes	None	None	Fixes in Clock Manager Various fixes in EMLIB and Peripheral HAL	None
Bootloader	3.1.1	July 21, 2025	Release Notes	None	None	None	None
Security	5.2.1	July 21, 2025	Release Notes	xG29 device family support API for Code region on External flash on Series-3 API for Data region on External flash on Series-3 LTO support for SE Manager components Migrated PSA Crypto Apps initialization to sl_main	None	None	None
Micrium OS	5.18.1	July 21, 2025	Release Notes	Restricted Micrium OS usage to Series 2 devices	None	None	None
CPC	4.7.1	July 21, 2025	Release Notes	Improved SPI driver compatibility for Series 2 & 3 devices Added preprocessor validation for UART RX buffer size without hardware flow control.	None	None	None
MVP Math Library	5.2.1	July 21, 2025	Release Notes	None	None	None	None
RAIL Library	2.19.1	July 21, 2025	Release Notes	None	None	None	None

Impact of Release Changes#

Impact Statements | Migration Guide

Impact Statements#

None.

Migration Guide#

sl_main migration:
- See the sl_system to sl_main migration guide for detailed instructions.
- Learn more about using sl_system_compatibility in baremetal applications here.

Using This Release#

Installation and Use | Help and Feedback

Installation and Use#

To run your first demo, see our Getting Started Guides.

To kick start your development, see our Developer's Guide.

For information about Secure Vault Integration, see Secure Vault.

To review Security and Software Advisory notifications and manage your notification preferences:

Go to https://community.silabs.com/.
Log in with your account credentials.
Click your profile icon in the upper-right corner of the page.
Select Notifications from the dropdown menu.
In the Notifications section, go to the My Product Notifications tab to review historical Security and Software Advisory notifications
To manage your preferences, use the Manage Notifications tab to customize which product updates and advisories you receive.

To learn more about the software in this release, dive into our online documentation.

Help and Feedback#

Contact Silicon Labs Support.
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SDK Release and Maintenance Policy#

See our SDK Release and Maintenance Policy.