Showing results for 
Search instead for 
Did you mean: 

Knowledge Base Articles

Unable to Connect PSoC 6 MCU After Programming Mbed OS or FreeRTOS Project - KBA232497


Unable to Connect PSoC 6 MCU After Programming Mbed OS or FreeRTOS Project - KBA232497

Author: VitaS_81           Version: **

Problem: Mbed projects created on top of mbed-os 5.14.0 release, once programmed into PSoC® 6 MCU, can lead to a permanent disabling of the debug port. Consequently, communication with the MCU will be lost; it will be not possible to reprogram or debug the firmware running on the device.

The same problem can happen when you use 201910.00 ModusToolbox WW1951 release of FreeRTOS from Cypress’ GitHub repository.

The following might be displayed in the ModusToolbox log window:


Update your Mbed OS / FreeRTOS version:

Mbed OS-based projects:
Ensure that your project is not based on the Mbed OS version 5.14.0, where the problem does exist. Mbed OS version is defined in <app_dir>/mbed-os/platform/mbed_version.h. If your Mbed OS-based project uses Mbed OS 5.14.0, update your Mbed OS to the latest version. Note that 99.99.99 is the default value for development version (master branch), so it is also recommended to update to the latest version.

FreeRTOS projects:
Use the latest version of FreeRTOS from the repository.

If you use Cypress Programmer:
Use Cypress Programmer with SFlash Restrictions set to "Erase/Program Sflash prohibited" as shown below:



If you use ModusToolbox:
Make changes to the corresponding ‘Debug/Program’ configurations. Do the following:

  1. Open Run > Debug Configurations, and select the appropriate Debug configuration.
  2. Find and remove the following line in the Config options as shown below:
    -c "psoc6 sflash_restrictions 1"



Repeat the same steps for the corresponding ‘Program’ configuration

Version history
Revision #:
1 of 1
Last update:
‎Jan 31, 2021 06:34 PM
Updated by: