Recently I started working with an LPC1768 development board and successfully programmed the board with a few different programs but when I wrote a program that switched the clock source from the internal clock to the main (12 Mhz) clock, the whole core became unresponsive. Any attempts to program or erase memory with J-Link have failed with error message stating no core found. I believe that the external oscillator may be faulty since the program worked fine before I changed the clock source.
Is there any way to program the device if it does not have a working clock (I know it boots to internal clock but very first line of code changes it to main oscillator) or will I have to fix the oscillator to get it running again?
Any help would be appreciated, thanks!
Thank you!
I tied the ISP pin to ground and it worked.
That is really good advice. I will definitely do that from now on, I just did not know that the JTAG interface required a clock on the device. I realized I had just stupidly missed the part about enabling the main oscillator before switching the clock source.