WiSeConnect - SiWx91x Platform SDK Version 4.1.1 (Jul 29, 2026) - Release Notes#

Wi-Fi 6 + BLE (WiSeConnect) SDK Version 4.1.1

Simplicity SDK Version 2026.6.1

The SiWx91x Platform Software Development Kit (SDK) provides platform features for Silicon Labs SiWx91x microcontrollers, including peripherals, drivers, and services.

See WiSeConnect releases for earlier releases.

Release Summary#

Key Features | API Changes | Bug Fixes | Chip Enablement

Key Features#

Added in 4.1.1#

None

Added in 4.1.0#

Added a Memory Manager Redirect component to redirect libc heap allocations to the CMSIS FreeRTOS heap_4 allocator by using heap wrappers.
Added support for a programmable I2C SDA hold time.

API Changes#

Added in 4.1.1#

None

Added in 4.1.0#

sl_status_t sl_si91x_secure_storage_write_register(mcu_secure_storage_register_t register_index, uint32_t value);
sl_status_t sl_si91x_secure_storage_read_register(mcu_secure_storage_register_t register_index, uint32_t *value);
sl_status_t sl_si91x_secure_storage_enable_protection_and_lock(void);

Bug Fixes#

Fixed in 4.1.1#

Fixed SLC validation failures when using WiseConnect with Simplicity SDK 2026.6.0.
Fixed an issue where the sl_si91x_mic application did not work when GCC LTO was enabled on the BRD2605A dev kit.
Fixed an implementation issue in the sl_si91x_adc_read_data_static() function.
Fixed an issue where the UART RS485 bare-metal and FreeRTOS applications did not work as expected on the BRD4342A PSRAM board.
Fixed an issue where sideband crypto did not work when input data was stored in flash memory.
Fixed an issue where debug prints did not work in projects created from an OPN when the Debug UC component was installed and ULP UART was enabled.
Fixed an issue where ChaCha20-Poly1305 operations with sideband crypto failed for payloads larger than 144 bytes.
Fixed intermittent NWP issues observed during AE + TCP maximum stress testing when logging was enabled.
Updated the SiWx91x Platform QEI example README to clarify hardware requirements and pin configuration guidance.
Updated the Hardware Requirements section by adding BRD4343C details and removing duplicate OPN entries.
Fixed an issue where SSI FreeRTOS primary and secondary data mismatched on the primary side on BRD4342A.
Fixed memory leak in the sli_memlcd_spi_tx() API.
Fixed an issue that could occur when switching between STA and AP modes due to unintended log activity during shutdown and unsynchronized updates to P2P status registers.

Fixed in 4.1.0#

Updated platform driver files to remove direct inclusion of FreeRTOS header files.
Removed the obsolete GY61 multichannel ADC sensor entry from sensorhub_config.c.
Fixed Si7021 sensor initialization failures with sleepy Matter applications.
Deprecated power manager APIs.
Fixed GPIO wrapper behavior to prevent output from being forced low and to allow configuration of the initial GPIO state.
Updated the information about ADC sample rate range in WiSeConnect SDK ADC examples and release notes.
Fixed I2C application behavior after waking up from calendar-based sleep.
Fixed HSPI secondary DMA loopback data corruption with 256-byte block size.
Enhanced peripheral component and README documentation.
Resolved documentation conflict for ULP_UART hardware flow control support.

Chip Enablement#

Added in 4.1.1#

None

Added in 4.1.0#

New radio boards added: BRD4343C
New chip components added: siwg917y110lgaxa, siwg917y110lgnxa, siwg917y111mgaxa, siwg917y111mgnxa, siwg917y121mgnxa, siwg917y121mgaxa

Key Features#

New Features | Enhancements | Removed Features | Deprecated Features

Note: See Feature Matrix for a list of any applicable APIs, examples, software variants, modes, hardware, and host interfaces applicable for each feature.

New Features#

Added in 4.1.1#

None

Added in 4.1.0#

Added DCH message type for ml_profiler on Si917.
Upgraded GCC to 14.2 and enabled Link Time Optimization (LTO) for GCC-based builds.
Added SDK support for SiWG917Y module refresh variants and XMC 8MB Flash boards.
Updated SiWx91x platform code to support BRD4002B Mainboard with EFR Driver Integration.
Incorporated the ARM CMSIS upgrade from v5.8 to v6.2 as part of the Simplicity SDK update used by WiSeConnect sample apps.
Added a Memory Manager Redirect component to redirect libc heap allocations to the CMSIS FreeRTOS heap_4 allocator by using heap wrappers.
Enabled sideband support for PSA crypto. (Note: Supported with PSA APIs and input buffers with M4 RAM).
Debug logger:
- SystemView is integrated.
- Debug Logger logging is not enabled by default for the NWP. Users who require Debug Logger logs must enable them manually by following the instructions provided in the SRM.
- Enabled IO Stream backend support (VCOM, RTT) on the SiWx917 platform.

Enhancements#

Added in 4.1.1#

None

Added in 4.1.0#

Improved PSRAM application support with updated jinja and linker configurations, a dedicated .log_fmt section, and IO stream trace support for ML profiling.
Updated peripheral application and component names from si91x to SiWx91x for naming consistency.
Decoupled PSRAM Core and PSRAM Device components, enabling independent component selection.
Updated the SiWx917 SVD file to incorporate the latest HRM changes and ensure alignment with the current register definitions.
Updated Startup and PSRAM linker files.

Removed Features#

Removed in 4.1.1#

None

Removed in 4.1.0#

None

Deprecated Features#

Deprecated in 4.1.1#

None

Deprecated in 4.1.0#

None

API Changes#

New APIs | Modified APIs | Removed APIs | Deprecated APIs

New APIs#

Added in 4.1.1#

None

Added in 4.1.0#


New API Signature	Deprecated API replaced by this (if any)
sl_i2c_driver_configure_sda_hold_time	None
sl_si91x_secure_storage_write_register	None
sl_si91x_secure_storage_read_register	None
sl_si91x_secure_storage_enable_protection_and_lock	None
sl_si91x_pcm_config_transmit_receive	None
sl_si91x_pcm_transfer	None
sl_si91x_i2s_transfer	None
sl_gpio_pin_configure_gpio_output_level	None
sl_si91x_iostream_set_console_instance	None
sl_status_t sl_si91x_adc_configure_clock	None
SLI_SI91X_POWER_MANAGER_CORE_ENTER_CRITICAL()	sl_si91x_power_manager_core_entercritical
SLI_SI91X_POWER_MANAGER_CORE_EXIT_CRITICAL(irq_state)	sl_si91x_power_manager_core_exitcritical
`SL_DEBUG_LOG_V2(...)`	`dummy_printf`

Modified APIs#

Modified in 4.1.1#

None

Modified in 4.1.0#

None

Removed APIs#

Removed in 4.1.1#

None

Removed in 4.1.0#

None

Deprecated APIs#

Deprecated in 4.1.1#

None

Deprecated in 4.1.0#


Deprecated API Name	Replacement	Planned Removal Date
sl_si91x_power_manager_sleep	sli_si91x_power_manager_sleep	2028-06
sl_si91x_power_manager_standby	sli_si91x_power_manager_standby	2028-06
sl_si91x_power_manager_core_entercritical	SLI_SI91X_POWER_MANAGER_CORE_ENTER_CRITICAL	2028-06
sl_si91x_power_manager_core_exitcritical	SLI_SI91X_POWER_MANAGER_CORE_EXIT_CRITICAL	2028-06
`void` `dummy_printf(const char *fmt, ...)`	`SL_DEBUG_LOG_V2(...)`	2028-06
sl_si91x_adc_configure_clock	—	2028-06

Bug Fixes#

Note: See the Feature Matrix section for a list of all hardware parts that work with the WiSeConnect SDK.

Fixed in 4.1.1#

ID	Issue Description	GitHub / Salesforce Reference (if any)	Affected Software Variants, OPNs, Boards, Modes, Host Interfaces
1685461	Fixed SLC validation failures when using WiseConnect with Simplicity SDK 2026.6.0.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1682446	Fixed an issue where the `sl_si91x_mic` application did not work when GCC LTO was enabled on the BRD2605A dev kit.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: BRD2605A Modes: SoC Host interfaces: N/A
1533235	Fixed an implementation issue in the `sl_si91x_adc_read_data_static()` function.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1676598	Fixed an issue where the UART RS485 bare-metal and FreeRTOS applications did not work as expected on the BRD4342A PSRAM board.	None	Firmware variants: Standard and Lite OPNs: All SiWG917 PSRAM-supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
1693912	Fixed an issue where sideband crypto did not work when input data was stored in flash memory.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1716168	Fixed an issue where debug prints did not work in projects created from an OPN when the Debug UC component was installed and ULP UART was enabled.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1731250	Fixed an issue where ChaCha20-Poly1305 operations with sideband crypto failed for payloads larger than 144 bytes.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1638463	Fixed intermittent NWP issues observed during AE + TCP maximum stress testing when logging was enabled.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1681802	Updated the SiWx91x Platform QEI example README to clarify hardware requirements and pin configuration guidance.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1680783	Updated the Hardware Requirements section by adding `BRD4343C` details and removing duplicate OPN entries.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: BRD4343C Modes: SoC Host interfaces: N/A
1670638	Fixed SSI FreeRTOS primary/secondary data mismatch observed on the primary side on BRD4342A.	None	Firmware variants: Standard and Lite OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
1666482	Fixed memory leak in `sli_memlcd_spi_tx()` API.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1535468	Fixed an issue that could occur when switching between STA and AP modes due to unintended log activity during shutdown and unsynchronized updates to P2P status registers.	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A

Fixed in 4.1.0#

ID	Issue Description	GitHub / Salesforce Reference (if any)	Affected Software Variants, OPNs, Boards, Modes, Host Interfaces
1410517	Removed direct FreeRTOS header file dependencies on the Wi-Fi SDK.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1564599	Removed the obsolete GY61 multichannel ADC sensor entry from `sensorhub_config.c`.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1580041	Fixed the Si7021 sensor initialization failures in the low-power (sleepy) Matter applications.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1595872	Deprecated power manager APIs.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1597421	Fixed GPIO wrapper behavior so output is not forced low and initial GPIO state can be configured.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1602498	Updated the documented ADC sample rate range in WiseConnect SDK ADC examples and release notes.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1628809	Fixed I2C application behavior after calendar-based sleep wake-up.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1634011	Fixed HSPI secondary DMA loopback data corruption with 256-byte block size.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1634996	Enhanced peripheral component and README documentation.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1646725	Removed `sl_si91x_usart_set_configuration()` function from the deprecated APIs list.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1638588	Added flash/FW overflow check in SoC and PSRAM linker files.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1673743	Resolved documentation conflict for `ULP_UART` hardware flow control support.	None	Firmware variants: Standard and Lite OPNs: All Boards: All Modes: SoC Host interfaces: N/A

Chip Enablement#

Added in 4.1.1#

None

Added in 4.1.0#

New radio boards added:

BRD4343C

New chip components are added under components/device/silabs/si91x/mcu/core/chip/component/:

siwg917y110lgaxa, siwg917y110lgnxa
siwg917y111mgaxa, siwg917y111mgnxa
siwg917y121mgnxa, siwg917y121mgaxa

Application Example Changes#

New Examples | Modified Examples | Removed Examples | Deprecated Examples

Note: See the Feature Matrix section for a list of all hardware parts that work with the WiSeConnect SDK.

New Examples#

Added in 4.1.1#

None

Added in 4.1.0#

Example Name	Description	Supported Software Variants (if applicable)	Supported Modes	Supported OPNs / Boards / OPN Combinations	Supported Host Interfaces
`SiWx91x Platform - ADC FIFO Mode FreeRTOS` See README	ADC FIFO example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ADC Static Mode FreeRTOS` See README	ADC Static example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP ADC FreeRTOS` See README	ULP ADC example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - Simple Button FreeRTOS` See README	Button example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP Timer FreeRTOS` See README	ULP Timer example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - Empty C FreeRTOS` See README	Empty C example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - Empty Cpp FreeRTOS` See README	Empty Cpp example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - GPDMA FreeRTOS` See README	GPDMA example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - GPIO Detailed FreeRTOS` See README	GPIO Detailed example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP GPIO Transition FreeRTOS` See README	ULP GPIO State Transition example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - GSPI FreeRTOS` See README	GSPI example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - Hello World FreeRTOS` See README	Hello World example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I2C Driver Follower FreeRTOS` See README	I2C Driver Follower example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I2C Driver Leader FreeRTOS` See README	I2C Driver Leader example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP I2C Driver Leader FreeRTOS` See README	ULP I2C Driver Leader example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I2S Loopback FreeRTOS` See README	I2S Loopback example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I2S Primary FreeRTOS` See README	I2S Primary example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I2S Secondary FreeRTOS` See README	I2S Secondary example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP I2S FreeRTOS` See README	ULP I2S example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - Joystick FreeRTOS` See README	Joystick example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - MEMLCD FreeRTOS` See README	MEMLCD example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - PCM Loopback FreeRTOS` See README	PCM Loopback example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - PCM Primary FreeRTOS` See README	PCM Primary example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - PCM Secondary FreeRTOS` See README	PCM Secondary example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - PSRAM Blinky FreeRTOS` See README	PSRAM Blink example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A	N/A
`SiWx91x Platform - PWM FreeRTOS` See README	PWM example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - SSI Master FreeRTOS` See README	SSI Master example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - SSI Slave FreeRTOS` See README	SSI Slave example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP SSI Master FreeRTOS` See README	ULP SSI Master example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - SDIO Secondary FreeRTOS` See README	SDIO Secondary example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - SYSRTC FreeRTOS` See README	SYSRTC example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - UART FreeRTOS` See README	UART example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - UART RS485 FreeRTOS` See README	UART RS485 example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - ULP UART FreeRTOS` See README	ULP UART example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - USART Asynchronous FreeRTOS` See README	USART Asynchronous example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - USART Synchronous Master FreeRTOS` See README	USART Synchronous Master example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - USART Synchronous Slave FreeRTOS` See README	USART Synchronous Slave example application enabled with FreeRTOS on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SiWx91x Platform - I/O Stream USART FreeRTOS` See README	Iostream-over-USART service sample using `sl_si91x_iostream_set_console_instance`.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - MCU Secure Storage` See README	Demonstrates MCU secure storage on the SiWx91x SoC device using secure-storage register APIs `sl_si91x_secure_storage_write_register`, `read_register`, and `enable_protection_and_lock`.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - SHT40 Sensor` See README	Demonstrates the SHT40 temperature/humidity sensor on the SiWx91x SoC device.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Logger Backend` See README	Demonstrates the `SL_DEBUG_LOG_V2` logger backend on the SiWx91x SoC device.	Standard	SoC	OPNs: All Boards: All	N/A

Modified Examples#

Modified in 4.1.1#

None

Modified in 4.1.0#

Example Name Changes Supported Software Variants if applicable Supported Modes Supported OPNs / Boards / OPN Combinations Supported Host Interfaces

Example Name	Changes	Supported Software Variants if applicable	Supported Modes	Supported OPNs / Boards / OPN Combinations	Supported Host Interfaces
`sl_si91x_pwm` See README	GPIO output level set before pin mux using `sl_gpio_pin_configure_gpio_output_level`.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`sl_si91x_ssi_slave` See README	SSI chip-select toggles per byte; 4343A pin documentation added.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`sl_si91x_uart`, `sl_si91x_usart` See UART README, USART async README	Multiple UART de-init restriction; SWO frequency correction.	Standard and Lite	SoC	OPNs: All Boards: All	N/A

sl_si91x_pwm

See README

GPIO output level set before pin mux using sl_gpio_pin_configure_gpio_output_level.

Standard and Lite

SoC

OPNs: All
Boards: All

N/A

sl_si91x_ssi_slave

See README

SSI chip-select toggles per byte; 4343A pin documentation added.

Standard and Lite

SoC

OPNs: All
Boards: All

N/A

sl_si91x_uart, sl_si91x_usart

See UART README, USART async README

Multiple UART de-init restriction; SWO frequency correction.

Standard and Lite

SoC

OPNs: All
Boards: All

N/A

Removed Examples#

Removed in 4.1.1#

None

Removed in 4.1.0#

None

Deprecated Examples#

Deprecated in 4.1.1#

None

Deprecated in 4.1.0#

The following baremetal examples are deprecated in favor of their corresponding FreeRTOS examples on the SiWx91x SoC device.

Example Name	Reason for Deprecation	Supported Software Variants (if applicable)	Supported Modes	Supported OPNs / Boards / OPN Combinations	Supported Host Interfaces
`SL Si91x - ADC FIFO Mode`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ADC Static Mode`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP ADC`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Button Baremetal`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP Timer`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Empty C Project SoC`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Empty CPP Project SoC`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - GPDMA`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - GPIO Detailed Example`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP GPIO State Transition Example`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - GSPI`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Hello World`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - I2C Driver Follower`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - I2C Driver Leader`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP I2C Driver Leader`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - I2S Loopback`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - I2S Primary`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - I2S Secondary`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP I2S`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - IOSTREAM USART Baremetal`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - Joystick`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - MEMLCD Baremetal`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - PCM Loopback`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - PCM Primary`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - PCM Secondary`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - PSRAM Blink`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A	N/A
`SL Si91x - PWM`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - SSI Master`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - SSI Slave`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP SSI Master`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - SDIO Secondary`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - SYSRTC`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - UART`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - UART RS485`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - ULP UART`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - USART Asynchronous`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - USART Synchronous Master`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A
`SL Si91x - USART Synchronous Slave`	Deprecated in favor of the corresponding FreeRTOS example.	Standard and Lite	SoC	OPNs: All Boards: All	N/A

Known Issues and Limitations#

Note: See the Feature Matrix section for a list of all hardware parts that work with the WiSeConnect SDK.

Added in 4.1.1#

ID	Issue or Limitation Description	GitHub / Salesforce Reference (if any)	Workaround (if any)	Affected Software Variants, OPNs, Boards, Modes, Host Interfaces
1694702	The sideband crypto buffer alignment requirement does not comply with the PSA Crypto API specification.	None	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1734857	AES-GCM decryption can overrun the output buffer by 16 bytes.	None	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1735621	Multipart SHA fails when multiple operations are interleaved.	None	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A

Added in 4.1.0#

ID	Issue or Limitation Description	GitHub / Salesforce Reference (if any)	Workaround (if any)	Affected Software Variants, OPNs, Boards, Modes, Host Interfaces
N/A	Floating point arguments are not supported with Debug Logger.	None	None	OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1662836	`CONFIG_MAX_ARGS` values less than 3 are not supported by the Debug Logger. The minimum supported number of logger arguments is 3.	None	The maximum number of arguments per log call is configurable within the range of 3 to 10.	OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1670763	In Coex configurations, the firmware may not report memory feasibility violations, which can result in runtime socket creation failures. The Memory Calculator correctly detects these conditions. Improvements are planned for a future release.	None	Use the Memory Calculator to validate memory feasibility before deployment.	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1662699	For application validation, performance measurements, and power testing, only the ERROR and WARN log levels are supported and recommended. Issues observed exclusively with the DEBUG log level should be considered debug-only observations and may not reflect normal production behavior.	None	Use only ERROR and WARN log levels for application validation, performance measurements, and power testing.	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
N/A	NWP (Captive Core) logging is not recommended for applications using the BLE Advertising Extension (AE) feature. Do not enable `SL_SI91X_ENABLE_NWP_LOGGING` in the `config_feature_bit_map` field of `sl_wifi_device_configuration_t` when BLE AE is enabled.	None	Do not enable `SL_SI91X_ENABLE_NWP_LOGGING` in the `config_feature_bit_map` field of `sl_wifi_device_configuration_t` when BLE AE is enabled.	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
N/A	NWP (Captive Core) logging is not supported for the lite firmware. Do not enable `SL_SI91X_ENABLE_NWP_LOGGING` in the `config_feature_bit_map` field of `sl_wifi_device_configuration_t`.	None	Do not enable `SL_SI91X_ENABLE_NWP_LOGGING` in the `config_feature_bit_map` field of `sl_wifi_device_configuration_t`.	Firmware variants: Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1606445	SSL Rx throughput may be lower than baseline due to frequent MCS rate dropouts during data transfer (under investigation).	None	None	OPNs: All Boards: All applicable Modes: SoC Host interfaces: N/A
1638531	When TEXT/DATA are placed in PSRAM, NOLOAD on BSS is ignored, causing BSS to be included in the image and increasing its size.	None	None	OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
N/A	LTO is not supported for PSRAM-enabled applications with LLVM or GCC toolchains.	None	None	OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
N/A	FreeRTOS tick-less idle mode is currently not supported in the Sensor Hub example application.	None	None	Software variants: Standard and Lite OPNs: All except IC's OPNs Boards: All applicable boards Modes: SoC, NCP Host interfaces: SPI, UART
N/A	UART instances do not support different FIFO thresholds.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1475241	SDC cannot be used with OPAMP as its input.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
N/A	The ULP Timer may experience timer drifts due to the inaccuracy of the clock source (RC oscillator).	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1527571	PSRAM can be used for runtime data storage as well as for executing MCU applications. It uses the instruction cache (I-cache) to improve instruction memory access performance. The PSRAM D-cache path is disabled to prevent incorrect data during specific back-to-back accesses. See DCACHE_E301 ERRATA for more details. Refer to the D-Cache Errata.	None	None	OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
N/A	Peripheral clock sources are currently fixed and cannot be configured by the user.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
N/A	GPDMA driver currently supports only memory-to-memory transfers.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
N/A	I2C receive operations using DMA may fail because the IC DATA CMD register must be programmed with a read command for each byte. Using two DMA channels (for programming the register and for data transfer) can lead to synchronization issues due to DMA flow control delays.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1567865	SSI Dual and Quad mode supports address lengths up to 32 bits only.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
N/A	The DMA controller does not support timeout or threshold interrupts for half-full or full states. For asynchronous transactions, the application must implement handshaking mechanisms to ensure proper synchronization and data transfer control.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
N/A	Only a few wakeup sources (ULP GPIO, ULP Timer, ULP ADC, ULP Comparator, and ULP UART) are currently supported for the PS1 state in the Power Manager.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1648684	SSL Tx/Rx throughput drop is observed in coex mode.	None	None	OPNs: All Boards: All Modes: SoC Host interfaces: N/A
1656537	WPA3 Wi-Fi reconnect fails with `sl_wifi_connect()` timeout (error 0x00000007).	None	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: All applicable Modes: SoC Host interfaces: N/A
1676598	UART RS485 baremetal and FreeRTOS applications do not work as expected on the 4342A PSRAM board.	None	None	Firmware variants: Standard and Lite OPNs: All SiWx917 PSRAM supported OPNs Boards: BRD4342A Modes: SoC Host interfaces: N/A
1623025	ULP SSI Master supports only CS1 due to hardware limitations on the BRD4343C board.	None	None	Firmware variants: Standard and Lite OPNs: All applicable Boards: BRD4343C Modes: SoC Host interfaces: N/A