Mbed OS 5.14.1 released

We are pleased to announce the Mbed OS 5.14.1 release is now available. This is the latest patch release based on the feature set that Arm Mbed OS 5.14 introduces.

Important note about this patch release

The Nanostack RF driver has been updated and as an exception to our normal release protocol, contains a breaking change.

Summary of PR changes

4-octet FCS which follows IEEE Std 802.15.4-2015 Bug fix related to channel spacing configuration

Impact of changes

This release contains version of a S2-LP driver which is not inter-operable with previous versions of the driver.

Migration actions required

To make previous version (Mbed OS 5.14.0) of the S2-LP driver inter-operable with this release, the following changes are needed.


@@ -553 +553 @@ static void rf_init_registers(void)

- rf_write_register_field(PCKTCTRL1, PCKT_CRCMODE_FIELD, PCKT_CRCMODE_0X1021);

+ rf_write_register_field(PCKTCTRL1, PCKT_CRCMODE_FIELD, PCKT_CRCMODE_0x04C11DB7);

@@ -556,0 +557 @@ static void rf_init_registers(void)

+ rf_write_register_field(PCKTCTRL2, PCKT_FCS_TYPE_FIELD, PCKT_FCS_TYPE_4_OCTET);

@@ -1001,0 +1003 @@ static void rf_receive(uint8_t rx_channel)

+ rf_channel_multiplier = 1;


@@ -251,0 +252,3 @@ extern "C" {

+#define PCKT_FCS_TYPE_FIELD 0x20

+#define PCKT_FCS_TYPE_4_OCTET (0 << 5)

+#define PCKT_FCS_TYPE_2_OCTET (1 << 5)

@@ -255,0 +259 @@ extern "C" {

+#define PCKT_CRCMODE_0x04C11DB7 (5 << 5)


In this release we have added the following targets:

  • ST DISCO-H747I
  • OKDO

Cypress targets have been updated to the latest PSoC 6 CSP (HAL, RTOS abstraction, Resource Abstraction). This update includes:

  • Minor bugfixes/code cleanup
  • Re-organization of resource/rtos abstraction folder structure
  • Documentation improvements

The Cypress Specific HCI Cordio Driver has also been updated to add:

  • MCU and BT device low-power support
  • HCI UART enhanced to work at 3M baud rate for improved BT performance. In order to put the UART interface at 3M baud rate the state machine for initialization has been modified
  • Updated BT device-wake pin drive mode from input to output mode to be able wake up the BT device from low-power state when needed
  • Added delays to BT device wake de-assert function to ensure that UART data is drained

We have provided an STM32H7 ST CUBE V1.5.0 update. The main impact of this update is the introduction of a Cortex-M4 instruction cache through ART accelerator.

We have had to disable tickless mode on UBLOX_EVK_ODIN_W2 as it appears to cause crashes in WiFi tests (Issue #11557). It will be re-enabled once this has been addressed.

This release also includes a Nanostack update to v11.3.0. This includes coap-service updates and bug fixes to the Wi-SUN protocol.

We have fixed the following reported issues:

  • 11295 QSPIFBlockDevice does not differentiate between mode (alt) and dummy cycles
  • 11362 Pin speed control
  • 11496 iar export: multiple -O in the project - fails to build
  • 10854 Mbed Os 5.12.4 ATHandler::resp_stop
  • 11508 LSI as RTC clock source on certain STM targets
  • 10880 VREFINT_CAL_ADDR wrong address for MTB_RAK811

We have also:

  • Added an initial implementation of Cypress Crypto hardware acceleration for mbedTLS
  • Re-enabled GCC/ARMCC support for RTL8195AM
  • Enabled asynchronous serial with DMA for K66F
  • Added flow control (IFC) into the BG96 AT driver

There are also a number of other fixes and code improvements.

For full details of this and previous releases, please visit our releases page.

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