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LPC824 Xpresso V2 OM13071 - xtal clock wont start

Question asked by lpcware Employee on Jun 15, 2016
Latest reply on Mar 13, 2017 by jeremyzhou
Content originally posted in LPCWare by larsen on Thu Nov 06 05:59:51 MST 2014
I have troubles getting the crystal clock to function on the LPC824 Xpresso V2 OM13071 (think its also called LPC824Xpresso-MAX although its the OM13071 which is written on the board).
And yes - I did move the position of jumper SJ3 and SJ4 to connect the 12MHz crystal.
The software is from here and is version 2.13.
To enable the xtal I changed the code in board_sysinit.c
void Board_SetupClocking(void)
/* Crystal is available on the board but not connected by default. */
/*Chip_SetupIrcClocking(); <----OLD */

so the xtal is setup instead of the onchip oscillator
What I see is that when debugging through the underlying code, it hangs in
while (!Chip_Clock_IsSystemPLLLocked()){} 

ie. the clock does not run. This is confirmed with an oscilloscope on the xtal.

I tried another board of my own design and this shows same behaviour. What can be wrong?
Missing switch matrix configuration? But Board_SetupClocking() should take care of that.
The supply voltage is 3.3V which is >1.9V as required by the errata note on LPC824xM.