LPC1125 run code exception

Guo2024 — Fri, 23 Aug 2024 10:08:47 GMT

Hi,Sir&Miss,

Good day.

LPC1125's embed flash bas been programmed with all zeros during production accidently.

Then I find the flash loader can not call the IAP commands again through the SWD interface.(flash loader is not from NXP,which is developmented by user-self refer to the ARM SWD debug protocol).

So I do another test to debug the LPC1125 to find the root cause by running some simple code.

First,I load the below Test1 code into LPC1125' embed ram,then I run the LPC1125 core by ARM debug port(SWD).The run entry address is the location of __asm("MOV R0,#0xAA"),and the bit0 should be 1.
I find that the LPC1125 core generates an exception when it executes the code __asm("MOV R0,#0xAA").So the code __asm("bkpt") can not be executed ok and the core can not be halted again.

/*Test1 code start*/
__asm("MOV R0,#0xAA");
__asm("bkpt");
/*Test1 code end*/

Second,I load the below Test2 code into LPC1125' embed ram,then I run the LPC1125 core by ARM debug port(SWD).The run entry address is the location of __asm("bkpt"),and the bit0 should be 1.
I find that the LPC1125 core can execute __asm("bkpt") ok and the core can be halted again.

/*Test2 code start*/
__asm("bkpt");
/*Test2code end*/

It looks that LPC1125 can not run the code __asm("MOV R0,#0xAA") ok since it will trigger an exception.

What should I do to recover the health(normal) running environment to execute the code __asm("MOV R0,#0xAA") ok?
Is there any way to write some registers to recover the device through SWD interface?
Show the detail command sequence on SWD interface will be best.

Thanks.

Re: LPC1125 run code exception

Alice_Yang — Mon, 26 Aug 2024 07:39:12 GMT

Hello @Guo2024

I recommend you low PIO0_1 pin when reset the chip. Then it run into ISP mode. Erase all flash, it can recovered to normal.

Alice

Re: LPC1125 run code exception

Guo2024 — Mon, 26 Aug 2024 07:56:55 GMT

Hi,Alice,

Thanks for your response.

Also I know what you said.

But it is not easy to do it since the device has been mounted on the PCB and there is no test point for PIO0_1 pin.

Would you help me find the solution only using the SWD interface?

Thanks.

Re: LPC1125 run code exception

Alice_Yang — Wed, 28 Aug 2024 10:05:05 GMT

Hello @Guo2024

Do you mean the chip can't be connect with SWD now? Do you have j-link debugger? Or LPC-link with J-LINK probe. If yes, try to use J-link commander to connect.

Alice

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