Freedom Board --- Warning about on-board Crystal / PLL

[#1]

WARNING

If you stumble across the "getting started page" FREEDOM BOARD / CORTEX M0+ GETTING STARTED Please take note:

While working with a large number of Freedom boards in a course,  it was observed that the Init Clock Routines would *sometimes* not work.    *Some* of the crystals on the freedom boards do NOT like "HIGH_GAIN" mode.  

change the line

  pll_init(8000000, HIGH_GAIN, CRYSTAL, 4, 24, MCGOUT);

to

  pll_init(8000000, LOW_POWER, CRYSTAL, 4, 24, MCGOUT);

[carxander]

That's because the resistor R25 is not already populated in the majority of the boards, those who have it not exhibit this problem.

[eli_hughes]

In all cases R25 was removed.

I also tried populating R25 in 2 boards and could still get the same result (1M).   Usually a *series* resistor is put in the EXTAL path to limit drive level.

[carxander]

My first freedom board had R25 populated, but the others 2 not. I tried

high gain in all of them and only worked in the first. I will try to

populate the others 2 and try high gain mode I will tell you the results...

2013/3/28 Eli Hughes <admin@community.freescale.com>

**

image: Freescale Community<https://community.freescale.com/index.jspa> Freedom Board --- Warning about on-board Crystal / PLL new comment by Eli

Hughes <https://community.freescale.com/people/eli_hughes> View all

comments on this document<https://community.freescale.com/docs/DOC-94311#comment-3682>