LPC55S06 Debug not working

[Ramdev]

Hi Team,

I am working with the LPC55S06 using MCUXpresso IDE.

I am currently using the power_manager_lpc example project with Power-down mode enabled. After flashing the code twice successfully, the following error started occurring when I try to flash or debug the application:

“SWD Configuration: 0 available SWD Devices detected. Connect a device and try again.”

Because of this, I am unable to debug or program the device. Although the USB port is still being detected by the system, the debugger is unable to detect the SWD device. I have attached snippet for the reference #LPC55S06 #NXP

[stephanie_m]

Hello, 

Please try using the ISP method described in this post

[LPC55]:Update Firmware in USB/UART/SPI/I2C-ISP Mode

Regards

[Ramdev]

Hi Team,
Thanks for the reply
We are currently using the LPC55S06 on our custom-designed board for a telematics application (not the EVK board).

While attempting to update the firmware using the MCUXpresso Secure Provisioning Tool in ISP mode, we are facing an issue where the "Write Image" function is not working. The tool reports a communication error during the connection process.

Additionally, we are encountering an SWD debug connection error in MCUXpresso IDE. As mentioned previously, the debugger is unable to establish a stable connection with the target device.

Since this is a custom hardware design, we would appreciate your guidance on the following:

Possible reasons why ISP write operation is failing on a custom board.

Steps to recover the device if it is stuck due to incorrect firmware or security configuration.

Recommended checks for resolving the SWD debug connection issue.

Kindly let us know if you require any additional details such as schematics, boot configuration, or log files for further analysis.

We look forward to your support in resolving this issue.

Regards,
Ramdev

[Ramdev]

Hello Team,
I would like to kindly request an update regarding my previous query. Please let me know if any additional information is required from my side.
I look forward to your response.
Thank you .

[Habib_MS]

Hello @Ramdev,

When you followed the steps regarding the Secure Provisioning Tool, what was the result after clicking the “Test Connection” button? Did it show “OK”, or did it report a failure?
Additionally, I highly recommend verifying your SWD connections according to the guidelines in the chapter “Debug and Programming Interface” of the AN13033: Hardware Design Guidelines for LPC55(S)xx Microcontrollers in order to avoid hardware issues.

Finally, if the hardware appears to be correctly connected but the device still does not respond, you may find this post useful. It describes methods to recover bricked LPC55Sxx devices that you can take by reference.
BR
Habib

[Ramdev]

Hello Team,

We used the MCU-Link tool with the SWD interface method and the Secure Provisioning Tool with UART pins P0_29 and P0_30. However,in both the method LPC5506 device is not being detected in secure provisioning tool with different baudrate.
Despite verifying the hardware connections and configuration settings, the device is still not recognized by the tool.

Could you please assist us in identifying the possible cause and provide guidance on how to resolve this issue?
Looking forward to your support.

[Habib_MS]

Hello @Ramdev,

Please verify all the board connections according to the recommendations from the hardware design guidelines I provided. At the same time, could you also check the functionality of the PIO_05 pin to put the board into ISP mode? For more details, please refer to the Boot Mode Configuration section of the hardware design guidelines.

Finally, if all the hardware seems to be working, please follow the instructions from the post I shared with you earlier. If that doesn’t work, you could try using blhost commands (which are used by the Secure Provisioning Tool). You can find the available commands in the blhost User’s Guide. If using blhost also doesn’t work, I’m afraid the MCU may not be recoverable.
BR
Habib

[stephanie_m]

hello, 

When working with low power mode, it would depend on the specific power mode if the SWD is disabled or not, and it is as expected behavior on the IDE when loosing SWD communication.

You can check in the ReadMe file of the example  power_manager_lpc — MCUXpresso SDK Documentation that it might disable some clocks , change pin states, etc.

Regards.

[Ramdev]

Hi Team,

Thank you for your response.

I understand that, depending on the selected low-power mode, SWD communication may be disabled and that losing SWD connection is expected behavior in such cases.

However, after running the power_manager_lpc example on the LPC55S06 using MCUXpresso IDE, I am currently unable to reconnect to the device via SWD. The IDE shows:

“SWD Configuration: 0 available SWD Devices detected. Connect a device and try again.”

Even though the USB port is detected, the debugger cannot detect the target device.

Could you please guide me on the proper recovery procedure for the board in this situation? Specifically:

What is the recommended method to regain SWD access after the device enters Sleep Power-down mode?

Should the device be recovered using ISP mode or a mass erase procedure?

Are there any specific jumper settings or hardware steps required to restore debug access?
Kindly provide the exact steps to recover the board and reprogram the device.