topic Re: LPC11E67 SWD Debug: "Wire ACK Fault in DAP access" in LPC Microcontrollers

LPC11E67 SWD Debug: "Wire ACK Fault in DAP access"

andrew_murfin — Thu, 14 Feb 2019 21:09:37 GMT

I'm attempting to debug the LPC11E67JBD48 via the recommended SWD connection (from page 75 of LPC11E6X datasheet), from an OM13058 board.

I am attempting this debug session in a brand new workspace, with the LPCOpen lpcu6x code. The debug configuration is basically the default. I have the proper jumpers on the OM13058 board (JP1 jumper connected; JP2 "Ext" pins jumpered together).

This is the main issue: When attempting to debug the following message comes up and puts me into a Hard Fault Handler:

And here is the debug console:

Interestingly, when running the "verify only" script in the GUI Flash Tool, it runs successfully. If I disconnect the SWD cable, it fails to connect to core. So it appears it is connecting to the MCU in some way. Below is the console of the successful "verify only" action:

It is interesting that it fails to see the target is an LPC11E67, not an LPC11U6X, although I'm not sure how much of a difference that makes. When running these same tests in a separate workspace, it was recognizing the target as an LPC11E67 but it was still having similar failures. I'm hoping since I am following the recommended debug connection schematics, it is not a hardware issue.

Thanks for any help!

-Andy

Re: LPC11E67 SWD Debug: "Wire ACK Fault in DAP access"

ianbenton — Fri, 15 Feb 2019 08:38:33 GMT

ACK fault is almost always a hardware problem, usually interference.

Is your supply at all noisy? Does it come from any type of switched-mode? Is there even a switched-mode nearby? Did a fly sneeze in a nearby building? If so, I suggest you read:

https://community.nxp.com/thread/462362

Though, strangely, more recent editions of MCUXPRESSO have improved the reliability.

Re: LPC11E67 SWD Debug: "Wire ACK Fault in DAP access"

nxf51211 — Fri, 15 Feb 2019 21:30:43 GMT

Hi Andrew,

I was able to debug with SWD (and with the OM13058) using only the jumper JP2 as you've described, but leaving JP1 unconnected. Besides this change, I also connected the board through the USB Target connection (not the one you use when debugging using the board only).

It is also important to mention that, if you had previously debugged the board directly (not using SWD) you first erase the debug configuration saved on your Project so that when you use SWD you can select it and get its proper configuration:

I hope this information can help you.

Ricardo Delsordo.