Zigbee SDK Version 8.2 (June 16, 2025) - Release Notes#

Zigbee Version 8.2

Simplicity SDK Version 2025.6.0

Silicon Labs is the vendor of choice for OEMs developing Zigbee networking into their products. The Silicon Labs Zigbee platform is the most integrated, complete, and feature-rich Zigbee solution available.

Silicon Labs EmberZNet SDK contains Silicon Labs’ implementation of the Zigbee stack specification.

Click here for earlier releases.

Release Summary#

Key Features | API Changes | Bug Fixes | Chip Enablement

Key Features#

• Updated filtering of InterPAN messages

• GCC Link Time Optimization (LTO)

• Added support for Tunneling functionality in Zigbee Direct.

• Improved status notification for packet sent

• Application Initialization Utilizing sl_main.

API Changes#

• sl_zigbee_af_incoming_packet_filter_cb

• sl_zigbee_af_outgoing_packet_filter_cb

• sl_zigbee_send_raw_message_with_tag

• sl_zigbee_af_zll_unset_factory_new

• sl_zigbee_gp_clear_proxy_table

• sl_zigbee_gp_proxy_table_remove_entry

• sl_zigbee_af_green_power_cluster_gp_sink_close_commissioning_window

• sl_zigbee_set_join_uses_install_code

• sl_zigbee_get_join_uses_install_code

• sl_zigbee_af_tc_link_key_update_now

• sl_zigbee_af_gpep_incoming_message_cb

• sl_zigbee_af_ncp_gpep_incoming_message_handler

• sl_zigbee_gpep_incoming_message_handler

• sl_zigbee_af_set_t_c_link_key_update_timer_milli_seconds

Bug Fixes#

• See Bug Fixes.

Chip Enablement#

• xGM260P PCB Module

• xGM270S SiP Module

• xG29 EFR32MG29B140F1024IM40

Key Features#

New Features | Enhancements | Removed Features | Deprecated Features

New Features#

• Updated filtering of InterPAN Messages
  Updated the message filtering mechanism to allow the inter-pan messages to be available to the application. This required the following updates:

  • Added new packet type SL_ZIGBEE_PACKET_TYPE_INTERPAN macro for general inter-pan message identification.

  • The existing packet SL_ZIGBEE_ZIGBEE_PACKET_TYPE_INTERPAN has been renamed to SL_ZIGBEE_PACKET_TYPE_INTERPAN_ZLL, based on the usage in the code.

  • The following callback names have been changed to better reflect their role in the processing pipeline:

    • sl_zigbee_af_incoming_packet_filter_cb → sl_zigbee_pre_incoming_packet_filter_cb (privileged)

    • sl_zigbee_af_outgoing_packet_filter_cb → sl_zigbee_pre_outgoing_packet_filter_cb (privileged)

  • Two new callback functions have been introduced to provide a more comprehensive filtering framework:

    • sl_zigbee_post_incoming_packet_filter_cb()

    • sl_zigbee_post_outgoing_packet_filter_cb()

  • These functions are called over IPC after the packet has been received / sent and processed by the privileged pre-filter callback. It is meant to be informative for the application task and doesn't affect the packet handling, which has already occurred.

• GCC Link Time Optimization (LTO)

  • Overview

    Link Time Optimization (LTO) is now enabled for Zigbee applications in this release for GCC. LTO is a powerful compiler optimization technique that allows the compiler to perform whole-program analysis and optimization at link time, resulting in improved code performance and, in some cases, reduced binary size.

  • Usage

    Installing the toolchain component toolchain_gcc_lto brings in the desired compiler and linker flags in a project.

    In 2025.6.0, the zigbee gcc SOC libraries are built with desired compiler flags (-flto, -ffat-lto-objects) to be compatible with the linker to perform LTO at the final linking stage. The gcc linker flag -flto gets added to the linker options when toolchain_gcc_lto is installed in a project and when it is not installed the -fno-lto flags will be required to be added. The SLC CLI or Simplicity Studio generation automatically updates the generated or updated gcc makefile. User maintained makefile must consider these flags to be forward compatible.

  • Key Benefits

    • Improved Performance: LTO enables more aggressive inlining and cross-module optimizations, which can lead to faster execution of Zigbee stack and application code.

    • Potential Code Size Reduction: By eliminating redundant code and optimizing across module boundaries, LTO may reduce the overall firmware size in some scenarios.

    • Better Optimization Opportunities: The compiler can optimize function calls and data usage across all source files, not just within individual files.

  • Considerations

    • Increased Stack and Heap Usage: Due to more aggressive inlining and function merging, LTO may increase stack and heap requirements. Stack sizes have been reviewed and updated in .slcp configuration files to ensure reliable operation under LTO.

    • Build Time: Enabling LTO may increase build times, as the linker performs more complex analysis and optimization.

    • Debugging: Debugging LTO-optimized binaries can be more challenging, as function boundaries and variable locations may change due to optimization.

  • Configuration Changes

    The toolchain_gcc_lto component is now included in Zigbee NCP and related projects. Stack size (SL_STACK_SIZE) configuration entries in .slcp files have been updated to ensure sufficient memory allocation for all combinations of LTO and RTOS usage.

  • Recommended Actions

    Review and test your application for stack overflows or memory issues, especially if you have custom code or third-party libraries.

    If you encounter issues related to stack or heap usage, consider adjusting the SL_STACK_SIZE and heap configuration values as needed.

  • Summary

    LTO is now part of the default build configuration for Zigbee applications, providing enhanced optimization and performance. Please review the updated stack size settings and test your applications accordingly to ensure a smooth transition.

• Application Initialization Utilizing sl_main.

  sl_system is deprecated in 2025.6.0 and is being replaced with sl_main. This means the existing apps main.c is not compatible with the new sl_main component. Therefore, it is recommended that if you have your own version of main.c, make it compatible with the new main.c provided by the sl_main component.

• Added support for Tunneling functionality in Zigbee Direct.

• New Green Power application framework APIs for commissioning window and GP Proxy Table entries Networking:

  To allow the management of green power proxy table directly by advanced users, two new public APIs are introduced:

  • void sl_zigbee_gp_clear_proxy_table(void);

  • void sl_zigbee_gp_proxy_table_remove_entry(uint8_t index);

  • Added following new Application framework API in green power server to close a commissioning session:

    bool sl_zigbee_af_green_power_cluster_gp_sink_close_commissioning_window(void);

• Improved packet failure status

  Updated the message sent by handler callback to report the status in case of error with more granularity.

  Following new status codes are introduced:

  #define SL_STATUS_ZIGBEE_ID_DISCOVERY_FAILED ((sl_status_t)0x0C1F) ///< Node ID discovery failed.
  #define SL_STATUS_ZIGBEE_NO_APS_ACK ((sl_status_t)0x0C20) ///< Message was sent but no APS ACK received.
  #define SL_STATUS_ZIGBEE_APS_MESSAGE_CANCELED ((sl_status_t)0x0C21) ///< APS message was canceled.
  #define SL_STATUS_ZIGBEE_ID_DISCOVERY_NOT_ENABLED ((sl_status_t)0x0C22) ///< Node ID discovery not enabled.
  #define SL_STATUS_ZIGBEE_ID_DISCOVERY_UNDERWAY ((sl_status_t)0x0C23) ///< Message was not sent, Node ID discovery is underway.
  #define SL_STATUS_ZIGBEE_SEND_UNICAST_ROUTE_DISCOVERY_UNDERWAY ((sl_status_t)0x0C24) ///< The message was not sent because a route discovery is currently underway. There is no route to the target until the route discovery completes.
  #define SL_STATUS_ZIGBEE_SEND_UNICAST_FAILURE ((sl_status_t)0x0C25) ///< Radius is 0 or message has been dropped because route request failed or failed to submit message to tx queue.
  #define SL_STATUS_ZIGBEE_SEND_UNICAST_NO_ROUTE ((sl_status_t)0x0C26) ///< No active route to the destination.
  #define SL_STATUS_ZIGBEE_BROADCAST_TO_SLEEPY_CHILDREN_TIMEOUT ((sl_status_t)0x0C27) ///< Broadcast message timeout while waiting for sleepy children to poll.
  #define SL_STATUS_ZIGBEE_BROADCAST_RELAY_FAILED ((sl_status_t)0x0C28) ///< Expected a neighbor to relay the message, but none did.

  The existing status codes that already get reported by the sent handler are listed here:

  #define SL_STATUS_OK
  #define SL_STATUS_FAIL
  #define SL_STATUS_MAC_NO_DATA
  #define SL_STATUS_CCA_FAILURE
  #define SL_STATUS_MAC_NO_ACK_RECEIVED
  #define SL_STATUS_TRANSMIT_INCOMPLETE
  #define SL_STATUS_ZIGBEE_DELIVERY_FAILED
  #define SL_STATUS_ZIGBEE_APS_ENCRYPTION_ERROR
  #define SL_STATUS_ALLOCATION_FAILED
  #define SL_STATUS_ZIGBEE_IEEE_ADDRESS_DISCOVERY_IN_PROGRESS
  #define SL_STATUS_ZIGBEE_KEY_NOT_AUTHORIZED
  #define SL_STATUS_NOT_FOUND

• Added new plugin feature: zigbee_memory_usage and zigbee_memory_usage_cli

  This component provides APIs and CLI commands for monitoring heap memory usage in Zigbee and Multiprotocol SoC and NCP applications. It allows applications to query the total heap size, current used heap size, and high watermark values both at runtime and immediately after initialization. This enables developers to track memory usage trends and optimize resource allocation. The CLI prints current and initialization-time heap statistics, while the API exposes functions for programmatic access to these metrics.

Enhancements#

• Enhanced Multi Rail Demo Component initialization

  The initialization of the Multirail Demo component initialization is enhanced to check presence of BLE component in the application project and allocate the third RAIL state buffer, if available, to be used by the multi rail demo plugin. That way it always leaves the second RAIL state buffer for BLE and as the 1st state buffer is always consumed by Zigbee stack in a Zigbee-BLE DMP application.

• Added CLI commands in zigbee_network_creator_security.slcc to toggle Allow TC Rejoin With Wellknown Key

  Added commands to control allowing of Trust Center rejoin with well-known key, along with a timeout.

• Added command to toggle RequireInstallCodesOrPresetPassphrase

  Added command to toggle TC require install code policy and introduced new stack APIs sl_zigbee_set_join_uses_install_code and sl_zigbee_get_join_uses_install_code.

• Two new applications have been added

  Zigbee - NCP CPC over UART link (zigbee_ncp_cpc_uart.slcp) and Zigbee - NCP CPC over SPI link (zigbee_ncp_cpc_spi.slcp).

  These are single protocol zigbee applications that connect to the NCP over a CPC connection.

• Enhancements to ZLL initialization for Zigbee Matter Light joining matter fabric

  ZLL initialization causes long delays in Zigbee Matter Light reconnecting to Matter Fabric. The sl_zigbee_af_zll_unset_factory_new() API has been added to allow applications to unset a Zigbee node from the default factory new state when necessary. A callback, sl_rail_mux_invalid_rx_channel_detected_cb(), has been added to Zigbee+OT applications. This callback notifies the application when there has been an attempted RX on two different channels while concurrent listening is not enabled. The application can then implement its own logic to handle this situation.

• Enhancements to Zigbee packages structure

  SLC "package" field values for components related to Zigbee and OpenThread have been adjusted in preparation for an upcoming SDK release format change in future.

• Enhancements to Network creator

  The Network Creator component has been updated to perform an energy scan followed by an active scan when determining a channel and PAN ID on which to form a network.

• Enhancements to network steering

  The VERIFY_TCLK state has been removed from the Network Steering plugin. This state was made obsolete, since the entire Trust Center Link Key update procedure as described in Zigbee 3.0, which comprises of the Node Descriptor, Request Key, and Verify Key exchanges, is handled by the stack. The end result of the TCLK exchange is handled by Network Steering via additional sl_zigbee_af_update_tc_link_key_status_cb invocations.

• Zigbee Direct enhancements

  Re-enabled the support for Curve 25519 in Zigbee Direct Device Light application.
  Legacy Network functionality for Zigbee Direct Device is now supported.
  Increased zigbee AF task stack and BT event handler stack size to fix device crash issue.

  Implement decryption of Tunnel command frame contents using the well-known global key for centralized security networks. An underlying bug, where the entire contents of input to sl_zigbee_sec_man_aes_ccm_extended was not copied over IPC was fixed. The API expects length+mic_length bytes of input to be copied over in the case of decryption. The doxygen for the API reflects to show this change.

• Zigbee Throughput component enhancements

  An optional uint8_t argument is added to the start command of the Zigbee Throughput component to configure its behavior regarding clearing counters. Calling "plugin throughput start 0" will leave counters uncleared, so testing that involves checking these values will work as intended in cases where counting may begin before the test starts.

Removed Features#

None.

Deprecated Features#

API Changes#

New APIs | Modified APIs | Removed APIs | Deprecated APIs

New APIs#

Modified APIs#

Removed APIs#

None.

Deprecated APIs#

None.

Bug Fixes#

Chip Enablement#

Application Example Changes#

New Examples | Modified Examples | Removed Examples | Deprecated Examples

New Examples#

Modified Examples#

None.

Removed Examples#

None.

Deprecated Examples#

None.

Known Issues and Limitations#