lpcware

USB PLL cannot be locked in lpc11u14

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by nickuse on Fri Sep 07 10:02:05 MST 2012
Dear All,
I download example code that is AN11232.
I try to running the HID+MSC+CDC example on LPC11U14.
but , it's always stop at SystemInit().


In function SystemInit()
  ....
  LPC_SYSCON->USBPLLCLKUEN  = 0x01;               /* Update Clock Source      */
  LPC_SYSCON->USBPLLCLKUEN  = 0x00;               /* Toggle Update Register   */
  LPC_SYSCON->USBPLLCLKUEN  = 0x01;
  while (!(LPC_SYSCON->USBPLLCLKUEN & 0x01));     /* Wait Until Updated       */
  LPC_SYSCON->USBPLLCTRL    = USBPLLCTRL_Val;
  while (!(LPC_SYSCON->USBPLLSTAT   & 0x01));     /* Wait Until PLL Locked    */  <------ stop there

  ....
 
The program always stop there, seems USB PLL cannot be locked.

Could you help me to solve this problem?

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