Andrea Pastega

MC9S08DZ60 32.789 kHz crystal external clock problem

Discussion created by Andrea Pastega on Jun 30, 2008
Latest reply on Jul 2, 2008 by Andrea Pastega
We are using Freescale MC9S08DZ60 microprocessors in our products. We had problems using these ICs with an external 32.789kHz XTAL using the first masks, as I discussed in my precedent post here:

http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&message.id=7237

Now we are in full production since some months, but we are reporting a 10% of the pieces reporting the same problems. The devices suddenly reboot itself, after a time variyng from a few of seconds to some hours. This problem is very bad to be discovered, as it isn't deterministic.
Normally the problem, when it appears frequently, is fully solved changing the uP on the PCBs, but of course this is awful, because the devices are very small and require the human operation of desoldering-resoldering. After that, we cannot undestand why the devices have this kind of behaviour, and if this problem is a known-case or not.  Note that if we modify the firmware to use the internal oscillator trimmed to almost the same frequency, the problem doesn't appear anymore, but of course the system isn't working well, because of the imprecise clock frequency.
All of this is very disappointing, especially from a brand like Freescale, comprehending that we need to lay the devices for a week turned-on and wait, to undestand if they "seem" to be working or not. And consider also that we are spending a lot of money to replace the "defective" processors, not to throw in the garbage the entire PCB.
Please give me the way on how to solve this!!!

PS-Where could I find mask errata for this IC? I have printed copies of 2M05C and 3M05C, but where can I find original PDFs in freescale website?
Thanks
    Andrea

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