LPC-link not working on custom board but JLink works

[lpcware]

Content originally posted in LPCWare by lpc1700user on Fri Nov 08 08:20:54 MST 2013
Just did  custom board using LPC1768 with SWD (SWDCLK and SWDIO) for programming/debugging.
Everything works fine using the J-link with Keil, but not with LPC-link and Code Red.

Code Red and LPC-link freeze when start debugger on the custom board, displaying:

LPCXpresso Debug Driver v5.2 (Jul  5 2013 11:31:15 - crt_emu_cm3_nxp build 15)
Looked for chip XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/LPC1768.xml
Looked for vendor directory XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/nxp_directory.xml
Found generic directory XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/crt_directory.xml

Progress bar: 94% (sometimes 97%).


The same project works fine when debugging LPCExpresso1769 in Code Red.

Custom board pull-up/pull-down:

SWDIO - PU 4.7K
SWCLK - PD 4.7K
/RESET - PU 4.7K
SWO - PU 4.7K (not connected, just pull-up)

ISP (P2.10) - PU 4.7K

Note: I did also the same pull-up/pull-down on the Expresso 1769 board and still working.

Does anyone has a similar situation?

Thank you.

[lpcware]

Content originally posted in LPCWare by LabRat on Fri Nov 08 13:29:02 MST 2013
I'm not sure how 'vector catch' is changing SWD behavior at LPC17xx today. A few years ago we scoped Reset & vector catch and there were differences...

[lpcware]

Content originally posted in LPCWare by lpc1700user on Fri Nov 08 12:57:52 MST 2013

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Quote:
Look at the schematic, there's a driver buffering Reset (in & out).

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Even the 74LVC125 output buffer has 3 state outputs, it seems like it is not driven to have a open drain RESET like other JTAG/SWD probes.

Thank you.

[lpcware]

Content originally posted in LPCWare by LabRat on Fri Nov 08 12:44:58 MST 2013

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Quote: lpc1700user
10K and 22K does not help.

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Then you have a hardware problem...

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Quote: lpc1700user
I think the issue is on the LPC-link reset output. Is it an Open drain output? (I will try to add an extra OD buffer)

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Look at the schematic, there's a driver buffering Reset ([color=#f00]in & out[/color]).

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Quote: lpc1700user
How do you guys power...

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3.3V...

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Quote: lpc1700user
... and connect LPC-link to your target?

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Minimal SWD connection: SWCLK, SWDIO, Reset, GND.

[lpcware]

Content originally posted in LPCWare by lpc1700user on Fri Nov 08 12:10:55 MST 2013
Thank you for replies.
10K and 22K does not help.

In the mean time I found the 3.3V system voltage drops significantly when LP-link assert the /RESET (not the same think happens with JLINK !), that explains the debugging issues.
On my setup, LPC-link is power by the USB, with no connection to the system 3.3V . The connections resume to:  SWDCLK, SWDIO, RESET and GND.

On the custom board there is a "OR"  using open drains outputs between ISP bus RESET (OD buffer), SWD RESET (LPC-link reset) and internal POR (ADM1816 - OD output).

I think the issue is on the LPC-link reset output. Is it an Open drain output? (I will try to add an extra OD buffer)

How do you guys power and connect LPC-link to your target?

Thank you.

[lpcware]

Content originally posted in LPCWare by LabRat on Fri Nov 08 08:54:14 MST 2013

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Quote: lpc1700user
Does anyone has a similar situation?

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We are using 2 pull-ups: 10k ISP and 22k Reset (must be greater than ISP). That's all. That's working here since 2009 with Link and Link2.

[lpcware]

Content originally posted in LPCWare by lpc1700user on Fri Nov 08 08:31:36 MST 2013
Below is the debug log, nothing else.

LPCXpresso Debug Driver v5.2 (Jul 5 2013 11:31:15 - crt_emu_cm3_nxp build 15)
Looked for chip XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/LPC1768.xml
Looked for vendor directory XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/nxp_directory.xml
Found generic directory XML file in C:/NXP/LPCXpresso_5.2.6_2137/lpcxpresso/bin/crt_directory.xml

The progress bar display 94%.
Note: there is traffic on SWD lines, but nothing will happen even after minutes.

[lpcware]

Content originally posted in LPCWare by lpcxpresso-support on Fri Nov 08 08:27:51 MST 2013
What does the debug log report?
http://www.lpcware.com/content/faq/lpcxpresso/debug-log