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LPCXpresso 8.2.0 debugging causes LPC-Link failure on previous versions

Question asked by George Mitsuoka on Aug 11, 2016
Latest reply on Aug 11, 2016 by George Mitsuoka

I have to downgrade from 8.2.0 because of the verified problem I reported yesterday here:


LPCXpresso 8.2.0 debugging sample code fails, 7.5.0 works


I am running LPCXpresso 7.5.0 on Mac OS X 10.11.6 and using the stock nxp_lpcxpresso_11c24_freertos_blinky code on an unmodified LPCXpresso LPC11C24 REV B card. I have used this setup many times in the past for large projects as well as with different code bases and different processors and boards.


After installing 8.2.0, trying to debug and finding the problem previously mentioned, I have found that 7.5.0 no longer works reliably.  When starting a debugging session, the debugger times out waiting for the LPC-Link to initialize:


Screen Shot 2016-08-11 at 11.03.15 AM.png

In addition, it appears that once an LPC-Link board has been used on my system with either 8.2.0 or 7.5.0 the board becomes unusable on other older installations (tested with 3 different LPC-Links and on a separate computer with 7.7.2 that has not had a later (post 7.7.2) installation. It times out on that system as well.


Through much trial and error, I've found that if I power cycle the LPC-Link, start a debugging cycle with 8.2.0 and then switch to 7.5.0 without power cycling the LPC-Link, it works. I can also power cycle the LPC-Link and run the following command line from the 8.2.0 bin directory:


./dfu-util -d 0x471:0xdf55 -c 0 -t 2048 -R -D LPCXpressoWIN.enc


I can then run 7.5.0 and the LPC-Link works.


From my testing, I am led to believe the following:


1. Debugging after 8.2.0 installation modifies the attached LPC-Link firmware

2. The new LPC-Link firmware is no longer compatible with the initialization code in older LPCXpresso installations

3. (1) happens even if the older installation of LPCXpresso is used (after 8.2.0 installation).


I realize it is probably a low-priority to fix problems with older versions of LPCXpresso, and I do have a PITA workaround, but if there is a way to patch the older installation with the newer LPC-Link initialization code, that would be extremely helpful.