Bartosz Cisek

9S08DZ - crystal problem

Discussion created by Bartosz Cisek on Sep 14, 2008
Latest reply on Sep 15, 2008 by erooll
Hi,

I develop my own board for master thesis. It's based on MC9S08DZ60. Initially I build very simple board (power supply, BDM programming head, one LED). Simple blinking LED program worked fine. I use witztronics.com debugger and CodeWarrior 6.2

Next step, was to enable precise clock. I used 12Mhz crystal and schematics from datasheet. Rs resistor was omitted because it should be used only with low frequency crystals. Board schematics is attached.

After power up, Code Warrior debugger tells me that it can't load diagnostics algorithm to target system, the chip is locked or derivative selected wrong. Few 'OK's later I can see that debuger detects target speed change and uC resets itself endless.

I removed crystal and related resistors and capacitors. It seems that I damaged uC because still can't program it.

I tried capacitors 18pF, 22pF, 27pF, 33pF, 39pF and 47pF(ceramic, 5%, smd 1206). Crystal 6MHz and 12MHz. Rf resistor 1MOhm and 3,3MOhm

Finally my question is: what might cause the problem? should I use Rs resistor?

Bartek

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