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[wxsig] Crashing and random characters

John Bennett jabennett at insightbb.com
Thu Jul 24 01:21:09 UTC 2008


Guy Story KC5GOI wrote:
> John Koster wrote:
>> Would there be useable date codes on the MCU chips.  Tracking those 
>> against problems might be helpful.  
>>
>> On Mon, 21 Jul 2008, William Beals wrote:
>>
>>   
>>> Guy (and all):
>>>
>>> Let me digest this for a bit.  While I don't know of it, there is a chance I
>>> do have something on the edge from a timing or voltage level standpoint that
>>> is going over the edge on the newer chips.
>>>
>>> will
>>>
>>> -----Original Message-----
>>> From: wxsig-bounces at lists.tapr.org [mailto:wxsig-bounces at lists.tapr.org] On
>>> Behalf Of John Bennett
>>> Sent: Monday, July 21, 2008 7:48 PM
>>> To: TAPR Weather Station SIG Mailing List
>>> Subject: Re: [wxsig] Crashing and random characters
>>>
>>> John Koster wrote:
>>>     
>>>> So am I drawing the right conclusion?  The processor chip from the T238+
>>>> kit was bad?
>>>>       
>>>>
>>> Wow. A bad MCU is not unheard of, but not in the quantity this would 
>>> indicate. I wonder if Motorola, in their infinite wisdom, changed some 
>>> of the timing parameters on writing to the EEPROM in a revision of the 
>>> chip. Might be worth looking into. I would sooner think that than a bad 
>>> bunch of MCUs.
>>>
>>> John
>>> n4xi
>>>     
> John, that is my diagnosis.  In response to the info you requested.
> 
> Suspect chip:
> Had sticker "1.15.3 or later TAPR t238"
> 
> MC68HC908GP32CP 3K08SCTQJ0433
> 
> Working chip:
> Had sticker "N0XGA WxSta Ver 1.11.1"
> 
> Same processor 3J20XCTAJ0003
> 
> John, John, and Will, depending on who whats it, I can send whom ever 
> wants it.
> 
> Guy
> 
> _______________________________________________
> wxsig mailing list
> wxsig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig
> 
The latter number is the one Motorola would need to check against for 
version changes or issues. It is the batch or lot number. The numbers 
leave a trail for tracking down issues like this.

Years ago Intel had the reputation of making memory chips that had 
access times that were never less than the advertised. For example, if 
they were rated at 200 nS, they would not work in a circuit designed for 
150 nS while other manufacturers chips of the same type would. I just 
hope Motorola has not started doing the same non-sense.

73,
John
n4xi





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