LPC4357 JTAG /SWD PROBLEM !

[lpcware]

Content originally posted in LPCWare by jrr_leon on Thu May 12 01:06:30 MST 2016
Hello,

I'm getting crazy... I made a 1st proto with a LPC4357 (based on the LPC4357-evb board). And It worked ok.

After that I've made a second version with some changes not related with the MCU... and  I'm unable to even discover the JTAG devices. I've soldered and unsoldered about 6 times the MCUS in 2 diferent boards, checked all the PINS.. the JTAG (on a 10 pin connector) signals... and everything is OK (except that the MCU doesn't answer).  After that I unsoldered the MCU into the old (working) PCB board and I soldered the new one... and the new one doesn't work. Happens the same whit it.

I tried to Pull up  the 2_7 pin (and also Pull down... just in case) nothing

The external oscillator doesn't start, But I tested it on the EVB and happens the same when there is not program burned.

The MCU power consumption is about 75mA and when I reset it goes to 5mA... then I think that the MCU is working.

The only difference is the MCU manufacturing date and silkscreen code (on the 2nd and 3rd line).

It's possible to have an issue into the lot?

Thank you very much !!! I don't know that happen.

[lpcware]

bump

[lpcware]

Content originally posted in LPCWare by jrr_leon on Thu May 26 01:10:46 MST 2016
Maybe... It's a very famous distributor...

But If SparkFun does...

[lpcware]

Content originally posted in LPCWare by MikeSimmonds on Tue May 24 08:09:16 MST 2016
Perhaps the bad lot (pun intended) were fakes.
I sure that NXP would like to have samples of these to test.
But don't blame the supplier right away, they were probably conned too.
It happend to SparkFun one time.

Just a thought, Mike.

[lpcware]

Content originally posted in LPCWare by jrr_leon on Tue May 24 04:40:14 MST 2016
Hello Bavarian,

The MCU is  LPC4357JBD208E with 3rd line: ESD15520A

Maybe I found the needle in the haystack.. because it's the first time that I've ever seen this too... But 8 MCUs in 2 different PCBs not working... The last test, solder 1 of the "wrong" version... don't work, same everything, just unsolder and solder the new... and It works. After that also replaced into the other PCB and it work too..

Regards,

[lpcware]

Content originally posted in LPCWare by bavarian on Tue May 24 03:01:14 MST 2016
I would be very interested in the date code of these chips (3rd line of the chip marking) which did not work.
We didn't face such a problem before, but I can't exclude it of course.

Regards,
NXP Support Team

[lpcware]

Content originally posted in LPCWare by jrr_leon on Mon May 23 06:12:57 MST 2016
Hello Bavarian,

Thank you for your help !.

I'm waiting for my distributor's to check it ... but at the end I'm 90% sure that It was the lot (or maybe the manipulation or transport?)

I bought new MCUs from other distributor (with another lot date) and  just unsoldering and soldering the new ones  It works perfectly !! ... It's the first time that I see sth. like this... but It happened. I tried it in 2 different boards with the same result, where the old lot didn't work (7 units tested) the new ones works perfectly.

Thank you !

[lpcware]

Content originally posted in LPCWare by jrr_leon on Mon May 23 03:50:52 MST 2016
Hello Bavaria,

Thank you for your help !.

I'm waiting for my distributor's to check it ... but at the end I'm 90% sure that It was the lot (or maybe the manipulation or transport?)

I bought new MCUs from other distributor (with another lot date) and  just unsoldering and soldering the new ones  It works perfectly !! ... It's the first time that I see sth. like this... but It happened. I tried it in 2 different boards with the same result, where the old lot didn't work (7 units tested) the new ones works perfectly.

Thank you !

[lpcware]

Content originally posted in LPCWare by bavarian on Mon May 23 03:16:46 MST 2016
Sounds tricky and confusing ;-)

Let me summarize this situation:
[list]
  [*]  It was initially working with one board + MCU
  [*]  With a new board and a new MCU it was not working
  [*]  You checked all differences and made crosschecks by changing/replacing the MCUs
  [*]  You now don't get it working again on both PCB versions
[/list]

What could be the reasons:
[list]
  [*]  JTAG/SWD port damaged:  check the voltage on the JTAG/SWD pins, if one of the pins is on an unclear level somewhere between HIGH and LOW, then the pin might be damaged. This could happen for example when connecting the powered JTAG debugger to the powered board. You could have have a huge voltage potential difference due to the different power supply domains and the current spike destroyed the pin. This can be avoided by connecting first GND1 to GND2, but when connecting the 10-pin debugger connector this cannot be ensured, one of the JTAG i/f pins could have been the first one.
  [*]  You have a firmware inside the chip which starts running after power-on and prevents somehow the access via JTAG/SWD. This could be solved by going into ISP bootmode P2_7 on LOW level) and access the chip via UART0 and the FlashMagic tool. You can also try to send a "?" to UART0, the chip should respond with an "OK".
  [*]  Your debugger box is damaged
  [*]  Last but not least ... you have overseen a hardware modification on your boards which prevents the chip to start correctly
[/list]

Some more notes:
[list]
  [*]  The 3.3V on the debugger connector is not really required
  [*]  For SWD you should have a pullup at least on the SWDIO pin
  [*]  External oscillator is not required, the chip starts with the internal 12MHz RC oscillator
  [*]  If you have USB, then you could try to boot in DFU mode and access the chip using the LPCScrypt tool
[/list]

Hope this includes some helpful information,
NXP Support Team

[lpcware]

Content originally posted in LPCWare by vtw.433e on Fri May 13 00:34:08 MST 2016
Sounds MUCH more likely that you circuit is wrong... Suggest you review it again, and again.

[lpcware]

Content originally posted in LPCWare by jrr_leon on Thu May 12 23:36:07 MST 2016
Hello Inspire,

I'm sure that after 6 MCUs almost one should be correct soldering :( . I use the LQFP packagin and the mark is in the correct position.  I'm quite sure (watching current consumption on normal and reset state... do you know another way to check it?) that the micro is working.

I bought another new micros from other distributor (praying for another lot) just to check if sth is wrong...

Thank you !

[lpcware]

Content originally posted in LPCWare by inspire on Thu May 12 11:15:06 MST 2016
Well, that's unusual. Of course, you can damage an IC if you torture it with too much and too long soldering heat. But if you carefully solder your device this shouldn't be a problem. Something else came to my mind: Did you place it with the right rotation on your PCB? So did you take the right pin 1 marking? Many LQFP LPCs have 3 round and lowered "dots" on their upper side but one is slightly different and this is pin 1.

[lpcware]

Content originally posted in LPCWare by jrr_leon on Thu May 12 06:15:54 MST 2016
Or maybe could be a soldering temperature problem ??

I usually solder this with heating air from my solder station. Once even I soldered it with with a normal solder and with ESD protection... and the same.

[lpcware]

Content originally posted in LPCWare by jrr_leon on Thu May 12 06:04:37 MST 2016
Hello inspire,

Thank you for your answer !

The changes are not related with this (LEDs. relocate...) and even I tried with a PCB w/o anything else mounted (just the MCU, Reset Pull-up and the clock (and w/o it) , and the JTAG PU resistors (All and only the 2 recoomented) and doesn't work.

The power is provided by a lab source.. and also I checked it on with the oscilloscope and it's ok. I tried with 5 different  MCUs.. all of the new lot and the same... "SWD communication ERROR"

The JTAG signals are on the MCU pins... and just in case I changed the cable of my ULINK2 programmer.

The point is that I tested another MCU of the the "suspicious" lot in into the old (and working ! ) board and  doesn't work, I don't have another MCU of the old lot to test into the new board (and after unsolder the older is unusable) .

Thank you !!! I've been one week with this and I'm desperate !

[lpcware]

Content originally posted in LPCWare by inspire on Thu May 12 03:54:06 MST 2016
Hi jrr_leon,

you mentioned that you made some changes not related to the MCU. Did you check the power supply? Are the 3.3V supply stable? Are the ground connections between your board and the debugger connected? Or maybe does the MCU heat up and get damaged because you connected e.g. a 12V signal directly to the LPC by mistake? I don't think that the lot is erroneous...they are usually tested. Or maybe you have an open via on you PCB? I once had one and this took me a long time to figure it out...it was a 3.3V via that was simply not connected to the power layer.