68300

Andret,
 
The CPU32 is very good about giving stack information.  When the machine takes a double bus fault, there will be a lot of information put on the stack.  If you will get that data and send it to me, I will try to help you decipher it.  
 
The most likely cause for a double bus fault is that there is nothing to "DSACK" the level 7 interrupt service routine.  However, the information put on the stack will help determine what is going on.
 
What you might have to do is write a short routine to dump the information on the stack.  If the machine simply halts, you can take the debugger and manually enable the stack memory and then read the stack memory through the debugger.
 
If none of this makes sense, send me an email and I will give more details.
 
Charlie

-----Original Message-----
From: Andrei Chichak [mailto:acpmiedm@...]
Sent: Tuesday, July 15, 2003 6:05 PM
To: 68300@yahoogroups.com
Subject: [68300] IRQ7 acting odd


Hi all,

I have a Benchmarq bq4842y battery backed ram RTC chip with INT* tied to 
IRQ7* directly (no pullup).

I have programmed PFPAR with a value of 0x80. DDRF is irrelevant but has a 
value of 0x13.

VBR is 0x100000. Location 0x10007C has 0x10E0C8 (address of the interrupt 
routine). Interrupt routine is declared as such and ends in RTE.

I have placed a breakpoint at the beginning of the interrupt routine (using 
SDS debugger) and the breakpoint never fires. When the RTC interrupt 
happens I can watch the INT* line go low and from that point on, when I try 
to halt the processor, SDS complains that it had to use a double bus fault 
to halt the processor. Prior to the interrupt the processor will halt properly.

If PFPAR is set to 0x00, I can always halt the processor properly even 
after the INT* line is asserted by the clock chip.

Any ideas?

Andrei

-------
Andrei Chichak               #200 10835-120 Street
Senior Software Developer    Edmonton, Alberta
Pulmonox Medical Inc.        Canada
                              T5H 3P9
                              (W) (780) 451-3660
                              (F) (780) 452-0169

Lat: 53° 33' 13.548" N
Lon: 113° 31' 43.164" W



Yahoo! Groups Sponsor	

ADVERTISEMENT
 <http://rd.yahoo.com/M=194081.3551198.4824677.1261774/D=egroupweb/S=1706554205:HM/A=1663535/R=0/SIG=11ps6rfef/*http://www.ediets.com/start.cfm?code=30504&media=atkins> click here	
  <http://us.adserver.yahoo.com/l?M=194081.3551198.4824677.1261774/D=egroupmail/S=:HM/A=1663535/rand=214399794> 	

---------------------------------------------------
To unsubscribe from this group, send an email to:
68300-unsubscribe@yahoogroups.com

To learn more about Motorola Microcontrollers, please visit
http://www.motorola.com/mcu <http://www.motorola.com/mcu> 



Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . 




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