RE: MPC555 strange double reset

There has been similar mails in the past.  The cause is often that the
part has come out of reset before the PLL has locked and a clock source
switch causes a HRESET.  The root cause for this is often too high a
pull-up on HRESET - try reducing to 1K or holding in reset slightly
longer by some other means.
 
- Allan
 

	-----Original Message-----
	From: [email protected] [mailto:[email protected]] On
Behalf Of dominique.gerard
	Sent: Wednesday, June 21, 2006 6:54 AM
	To: [email protected]
	Subject: [MPC500] MPC555 strange double reset
	
	

	Dear all,
	
	I'm developping a motor control project with the MPC555 (at the 
	moment, our board have the following processor MPC555LFAZP40).
	
	I have discovered the following strange fact :
	The processor seems to perform two times my initialisation
procedure.
	
	The problem is that for instance I can not explain why I have
this 
	strange phenomenon (I'm looking for the root cause for some
weeks but 
	now I'm no more ideas : PORESET signals, internal watchdog have
been 
	excluded to be the cause of this RESET).
	
	I have modified my software in order to send through a RS232
link the 
	RSR register value and the figure 0xC0B8 seems to be the last
code 
	value of the last "reset" cause (Loss of lock reset status). The

	problem is that I can not explain why I have this value in the
RSR 
	register.
	
	Apparently, some guys already had a similar problem 1 or 2 years
ago 
	("strange reset" keyword in the past messages).
	
	Does anyone know if this problem has already been found and
resolved ?
	
	Does anyone have any idea in order to solve the problem ?
	
	Thanks
	
	

	 



[Non-text portions of this message have been removed]



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