MCUXpresso can't access the lpc11u68 after the first time of debugging.

[wangwenyu]

I use MCUXpresso to connect my target board through a MCU-Link pro. The target board is a simple system on which a LPC11U68 connects a NTAG plus chip through IIC. The ROM driver is used.

It works properly at the first time when I debug this board. But, after I repower the target board, the MCUXpresso never connects with the target board again. This problem continuously occured on my 5 boards. The first time always works. Then the MCUXpresso never connects the target again. 

It is highly appreciated if some body help me.

I have struggled for 4 days. No clue is found. 

[lpcxpresso_supp · Accepted solution]

I'm tempted to say that Code Read Protection was accidentally enabled on your MCUs. Please take a look in the User Manual:

Also, a quick inspection of the projects you attached, illustrate that address 0x0000_02FC is populated with actual implementation of "HW_setup_Board_for_use_with_NTAG" function, meaning that CRP is affected.

I suggest you create a sample project using the NPW from the IDE and inspect "crp.c and "crp.h".

Moreover, please take a look at the generated linker script.

There's also an application note that might be useful: https://www.nxp.com/docs/en/application-note/AN10968.pdf

Regards,
MCUXpresso IDE Support

[wangwenyu]

Hi. Not lucky

I used a brand new board (a new MCU) and added the .crp section. But the problem still exists

There is __CRP const unsigned int CRP_WORD = CRP_NO_CRP; in the cr_startup_lpc11u6x.c

[lpcxpresso_supp]

Obviously... It won't work if you simply add the CRP section now. Your MCUs are most likely locked and debug access is no longer possible because of the previously generated incorrect images. Have you looked in the CRP-related header I suggested? There are comments that mention tools to recover your MCUs.

Regards,
MCUXpresso IDE Support

[wangwenyu]

 It is a brand new board. It worked with the simulator at the beginning. I successfully debug this board with a new built image which already NO-CRP at 0x2fc according to your suggestion. (see the image in the last post)

unfortunately, it is locked after I reconnected it.  

I have 4 boards left. 6 Boards are dead.  Hope I can get a clue before I try the next board.

Thank you!

@lpcxpresso_supp 

[wangwenyu]

I forgot to tell that it is a brand new board. It worked with the simulator at the beginning. I successfully debug this board with a new built image which already no-crp at 0x2fc according to your suggestion. 

unfortunately, it is locked after I reconnected it. 

There isn't UART circuit on this board. It isn't possible to recover the board. Flash Magic doesn't support USB for the LPC11U6x.

[wangwenyu]

Thanks. 

I have to enable "Enable automatic placement of code read protection field in image".

Then I have:

Let me try it. Thank you again