maik brombach

HC(S)08DZ - crystal stays silent

Discussion created by maik brombach on Oct 28, 2011
Latest reply on Oct 28, 2011 by bigmac

Hi everyone,

 

I'm new to freescale's micro controllers. I was recommended the hcs08 for their internal CAN Controller, high stability and small package.

At the moment I'm trying to start external crystal for CAN clocksource, but I'm really getting nuts, because the crystal stays silent. I looked for some reference code in here and found something like the following:

 

SOPT1_COPT = 0; /* disable COP */
SOPT2_MCSEL = 1; /* enable MCLK. MCLK = BUSCLK/2 */
PTGDD = 0xfe; /* EXTAL Input, XTAL Output */
MCGC2 = 0x36; /* RANGE HF, High Gain,External Reference Selcet Oscillator, MCGERCLK active */
while (!MCGSC_OSCINIT);

 

Debugger halts at oscillator initialisation, and the flag won't be set. With a 8pF probe, i won't see anything but the crystall should be swinging here, right?

 

I changed Crystal and capacitor up and down and I'm still missing reaction.

Q1 = 16MHzQ2=7.3 MHz

C1/2= 10-18pFC1/2=12pF

Rf= infinite/ 1MOhm

Rs=0

 

Can anyone help me out, I'm getting nuts fixing the bug.

 

thank you very much

Maik

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