lpcware

LPC1114 without external crystal

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by chucks13 on Mon Mar 07 11:46:33 MST 2011
Hello, I am new to the forums, so if the is an FAQ, please forgive me

I have a target board based on the LPCXpresso 1114 board. My target board has no crystal, because I was assured that it run without it using the PLL to drive the system clock, up to at least 48 Mhz, and hopefully 50. The standard examples which I believe are suppose to activate the PLL have on this line:
  while (!(LPC_SYSCON->SYSPLLSTAT & 0x01));          /* Wait Until PLL Locked    */

This is in the library SystemInit() function. My board makes it to this line and hangs. The obvious reason is that the PLL never acquires a lock. I have not made any changes to the initialization code.

I fear that I have missed something, like an external resistor that the LPCXpresso  board with the crystal doesn't need, or the standard examples  needs something more.

Thanks for reading my post.

Chuck

Outcomes