Can't communicate with a LPC11A04UK

[lpcware]

Content originally posted in LPCWare by keithco on Tue Oct 29 09:25:14 MST 2013
We have not been able to connect, via SWD to any of our 15 boards that utilize the LPC11A04UK  WLCSP-20 part.
I screams that the processors are dead.
Convinced the first assembly shop damaged the parts, we sent 5 boards out to a different assembly shop and had them remove and reinstall new parts with the same result. |(
See attached schematic and screen shots of the what we are getting every time.
Please let us know if you see anything suspicious...

Forgot to mention, J1 does have a ground connection (not shown) in this pic.

Thanks,

Keith

[lpcware]

Content originally posted in LPCWare by Alainbs on Thu Feb 06 05:18:23 MST 2014
Hi,


Does the LPC-Link2 support the LPC11A04 MCU?.



http://www.nxp.com/knowledge-base/50809/1111285

Why does LPC-Link not work with the LPC11A02 and LPC11A04?

The LPC-Link communicates with LPC11A02/04 through the SWD pins. The SWD pins on the LPC11A02/04 have glitch filters enabled by default. The LPC-Link operate at a speed which gets filtered out by the glitch filter. To use LPCXpresso with the LPC11A02/04, please use the Red Probe debugger which allows changing of the SWD clock frequency.

Cheers!
Alain

[lpcware]

Content originally posted in LPCWare by Alainbs on Tue Feb 04 01:28:57 MST 2014


http://www.nxp.com/knowledge-base/50809/1111285


Why does LPC-Link not work with the LPC11A02 and LPC11A04?

The LPC-Link communicates with LPC11A02/04 through the SWD pins.  The SWD pins on the LPC11A02/04 have glitch filters enabled by default.  The LPC-Link operate at a speed which gets filtered out by the glitch filter.  To use LPCXpresso with the LPC11A02/04, please use the Red Probe debugger which allows changing of the SWD clock frequency.

[lpcware]

Content originally posted in LPCWare by tha on Tue Oct 29 14:15:41 MST 2013
For the CSP packages, the SWD pins are mux with the I2C pins, which are true open drain pins.  For the SWD connection to work, pull-ups are needed.

[lpcware]

Content originally posted in LPCWare by TheFallGuy on Tue Oct 29 13:38:00 MST 2013
Do you have pull-ups on SWDCLK and SWDIO. As stated in  chapter 24 of the User Manual:

SWCLK Serial Wire Clock.
This pin is the clock for debug logic when in the Serial Wire Debug mode (SWDCLK). For the SWD function, a pull-up resistor is recommended on this pin.
SWDIO Serial wire debug data input/output.
The SWDIO pin is used by an external debug tool to communicate with and control the LPC11Axx. For the SWD function, a pull-up resistor is recommended on this pin

[lpcware]

Content originally posted in LPCWare by R2D2 on Tue Oct 29 11:01:40 MST 2013

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Quote: keithco
No. I don't have hardware that supports this.
Can you share your thoughts why we would try this??

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That's at least my usual procedure to get my boards working. If SWD fails, ISP is the next step.

If ISP is not working, then there's a serious hardware problem.

ISP is still the best way to test hardware, more reliable than SWD. 

Just connect a FTDI and start FlashMagic...

[lpcware]

Content originally posted in LPCWare by keithco on Tue Oct 29 10:51:02 MST 2013
No. I don't have hardware that supports this.
Can you share your thoughts why we would try this??

[lpcware]

Content originally posted in LPCWare by R2D2 on Tue Oct 29 10:18:58 MST 2013
Did you disconnect your 485 and connect something serial to use ISP also?

[lpcware]

Content originally posted in LPCWare by keithco on Tue Oct 29 09:55:55 MST 2013
Yes! Tried this multiple times....
And of course added a 10K pull-up on B2..

[lpcware]

Content originally posted in LPCWare by R2D2 on Tue Oct 29 09:43:25 MST 2013
Did you try to boot into ISP (B2 low) already?