Can't connect to LPC11A04UK

[lpdion]

Hi,

I've tried to communicate to the LPC11A04UK (WLCSP20 package) without success. I'm using the LPC-Link-2 CMSIS-DAP V5.173

I get the following error message : 

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02 : Failed on connect

Could not connect to core.

Emu(0): Connected&Reset. Was: Not Connected. DpID. CpuID: 000000. Info <None>

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I'm using PIO0_0 for Reset, PIO0_1 for ISP, PIO0_2 for SWCLK and PIO0_3 for SWDIO.

I added pull-up resistors (100K) on SWCLK and SWDIO close to the LPC11A04UK (Note : I've seen no difference with or without the pull-ups on SWDIO and SWCLK).

I shorted JP2 on LPC-Link-2. Note that my PCB has his own 3.3V. Just in case, I have also tried to use the 3.3V from my PCB to supply the SWD on LPC11A04's side (so JP2 off), but no change.

I didn't shorted JP1.

I use J7 header on LPC-Link-2 to communicate with the target.

I have scoped the Reset and the ISP signals on the LPC11A04UK and they are both pulled down at the beginning.

I have verified the connections of the SWD signals between the LPC4370 (on the LPC-Link-2) and the LPC11A04UK and it is OK.

I have tried several debug configurations, including the one if the attachment.

Every board I tried gave the same error message, as displayed previously.

I joined a scope of SWDIO and SWCLK as a reference.

Also, my communication with the LPC4370 seems to be OK since I can manually program a script (program_CMSIS) in it.

Any suggestions to help ? I'm out of ideas.

Regards,

Louis-Philippe

[jeremyzhou]

Hi Louis-Philippe Dion ,

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
It must ensure the JP2 be closed if you want to use the LPC-link2 as the debugger.
Meanwhile, I was wondering if you can share the SCH of your customized board.
Have a great day,
TIC

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[lpdion]

Hi,

Here is my schematics around LPC11A04UK.

His footprint looks good to me and the power supply of 3.3V is OK.

Also, I tried the secondary SWD port (PIO0_5 and PIO0_10) : it won't work.

Thanks,

Louis-Philippe

[jeremyzhou]

Hi Louis-Philippe Dion ,

Thanks for your reply.
Recommend: It must ensure the JP2 be closed if you want to use the LPC-link2 as the debugger.
In further, you can refer to the schematic of MCB1000 to correct your own one, please checking it.
Have a great day,
TIC

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[lpdion]

Hi, 

Yes, JP2 is closed. Also note that the pull-ups on SWDIO and SWCLK that i added are not shown on my SCH.

About what you proposed, the MCB1000 do not use the same MCU as our. Our problem is really with the LPC11A04 since we have been able to connect with the LPC11U24 (with a different program of course).

The only difference i see in our PCB is the absence of an external crystal, but the chip is suppose to be running on IRC, see the following directive from the datasheet : 

« Following reset, the LPC11Axx will operate from the IRC until switched by software. This allows systems to operate without any external crystal and the bootloader code to operate at a known frequency. » [p.34 of LTC11A04 datasheet)

I'm sure our RESET is OK since i have a different error message if i don't reset the chip (or if i don't pull ISP LOW), which is «Target marked as not debuggable». It looks normal to receive such an error since we need the RESET to use PIO0_2 and PIO0_3 for SWD. If my circuit was not OK, i think i would still get that error message...Now, the message i get is really the one i said in my first message, which is « Could not connect to core »

Fun fact, the script i use to connect with both the LPC11U24 and LPC11A04 is « LPC11AXXConnect.scp » and it only works with LPC11U24...

Is the debug configuration file i gave you earlier looks fine to you ?

I still feel that the problem is related to LPC-Link-2... Is there any demoboard that use the LPC11A04 ?

Also, when i try to flash my code, i saw LED1 of LPC-Link-2 flashing which means the bit BOOT0 changes state. Is that normal ? I don't see such behaviour with the LPC-Link1.

Thanks,

Louis-Philippe

[jeremyzhou]

Hi Louis-Philippe Dion
Thanks for your reply.
1) Is the debug configuration file I gave you earlier looks fine to you?
-- It seems correct.
2) Is there any demo board that uses the LPC11A04?
-- No, there's no demo board for LPC11A04.
To validate the hardware circuit, I'd like to suggest you follow these below steps to connect the LPC11A04.

• Updating the LPC-link2 with J-Link firmware.
• Open the J-Link Commander to connect the chip.

Have a great day,
TIC

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[lpdion]

Hello,

I've updated the LPC-Link-2 with J-Link firmware and i tried to connect to LPC11A04 using the J-Link commander like you suggested and it still failed to connect...

From the SCH i gave you, have you seen any bad connections (except for the pull-ups on SWDIO and SWCLK that i later added) ?

Could you confirm that we don't need an external crystal on our PCB ?

Have you heard of similar problems with the LPC11A04UK (WLCSP20 package) ?

Is there anything else i can try ?

Thanks a lot for your time & help,

Louis-Philippe

[jeremyzhou]

Hi Louis-Philippe Dion

Thanks for your reply.
1) From the SCH i gave you, have you seen any bad connections (except for the pull-ups on SWDIO and SWCLK that i later added) ?
-- No, however, the issue definitely is related to hardware circuit according to your testing, I think you'd better check the PCB carefully.
2) Could you confirm that we don't need an external crystal on our PCB ?
-- The LPC11Axx can work with internal crystal, the external crystal is not necessary.
3) Have you heard of similar problems with the LPC11A04UK (WLCSP20 package) ?
-- No.
Have a great day,
TIC

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