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

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by ramniraj10 on Sun Mar 15 22:02:59 MST 2015
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.

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.

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.