LPC812 SWD clcok frequency is higher to download to flash and debugging[SOLVED]

[lpcware]

Content originally posted in LPCWare by ramniraj10 on Sun Mar 15 22:02:59 MST 2015
Set-up:
Keil ulink2(firmware version v2.02 and lpc812)

NOTE: May be this topic is related to ulink2 but it is generic.

Issue: Binary download fails at SWD clock frequency lower than 5 MHz with above set-up.
Earlier, it was fine and could lower the clock frequency to 100 KHz to download binary and debug the code.

I have reported this issue to KEIL also.

Report:
Earlier when using same set-up(ulink2 and LPC812) and SWD maximum clock frequency up to 1 MHZ. Lowering the clock upto 100 KHz can download and debug the code  in LPC812.

Right now using same set-up and ulink2 and with new LPC812 micro controllers, it could not work well
SWD clock frequency is now 5 or 10 MHz for downloading and debugging.
Binary download fails 3(out of 10) times.

Debugging @ 10 MHz always stops after 15 seconds.

Query:
1. What is the maximum SWD clock frequency of lPC812?
2. Can LPC812 SWD communication fails below 1 MHz? Because it is happening here. SWD communication fails below 500 KHz.
3. Why this issue happened now after 1 year of testing? Can anyone share the proper working SWD connection(wiring) diagram with Ulink2 and KEIL MDK5?
4. Checked with different power supply and 4 LPC812 micro-controllers.

[lpcware]

Content originally posted in LPCWare by ramniraj10 on Wed Apr 29 01:57:16 MST 2015
Dear whitecoe,

I have followed each of NXP and lpc xpresso board concepts and layout.

With ulink2 and 20 pin connector, it was working fine.
As i didn't had 10 pin(50 mil) connector at that time, i tried to manage with debug circuitry with 20 pin only.

I connected SWDIO, SWCLK and RESET all three lines, but it was not working at all.
When the same circuitry used with 10 pin (50mil) conenctor for SWD, it worked normally and I can download code and debug at any frequency.

May be the issue with 20 pin conenction.

Thanks,
Niraj Ram

[lpcware]

Content originally posted in LPCWare by whitecoe on Wed Apr 29 00:19:13 MST 2015

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Quote: ramniraj10
The issue was due to 20 pin(100 mil) connector of Ulink2 was used.
After moving to 10 pin(50 mil) connector for SWD, problem do not occur and is working great.

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So maybe an issue between your connector and your debug/reset circuitry. Did you check out the recommendations at http://www.lpcware.com/content/faq/lpcxpresso/debug-design, or maybe the schematics for some of NXPs boards like the LPC812-MAX (http://www.lpcware.com/content/devboard/lpcxpresso-max-developer-boards) ?

HTH!

[lpcware]

Content originally posted in LPCWare by ramniraj10 on Tue Apr 28 21:53:44 MST 2015
The issue was due to 20 pin(100 mil) connector of Ulink2 was used.
After moving to 10 pin(50 mil) connector for SWD, problem do not occur and is working great.

A request to NXP.
I have ordered a lot of 200 micro-controllers. Out of which 10 were destroyed just because of above issue.
Also, i am on the way to order 1000 PCs for next project.
I can't find any help or support from NXP team, so it will impact on my time spent on project code development.
I am an embedded engineer but trying to do simple hardware design myself. So, could be there are some silly issues which you can solve in time.

Another issue i have logged in which is so simple that any NXP expert can answer, but i have to wait for a long time to get any answer for it.

Thanks,