Re: MC68020 Embedded System HW Reset Problem - Need Help
- From: Didi <dp@xxxxxxxxxxx>
- Date: Wed, 28 May 2008 22:08:45 -0700 (PDT)
Jim Flanagan wrote:
....
There are times when the unit is powered up, that the 68020 will not
reset properly and simply locks up. Upon investigation, I have
determined that a double bus fault has occurred.
Most likely the reason for the double bus fault is some problem
during reset code execution. May be some memory or peripheral
does not respond (does not assert the DSACKx line(s) etc.).
A very likely reason would be some "forgotten" bit in the flash or
eprom;
if the 68020 tries to access a non-decoded address during reset
and gets a BERR, here you go, it will halt because of a double bus
fault.
Dimiter
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Dimiter Popoff Transgalactic Instruments
http://www.tgi-sci.com
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http://www.flickr.com/photos/didi_tgi/sets/72157600228621276/
Original message: http://groups.google.com/group/comp.arch.embedded/msg/60bec024c19a42e7?dmode=source
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