Graham Pratt

Unused INT trap. RTI or send to start of prog?

Discussion created by Graham Pratt on Jul 7, 2013
Latest reply on Jul 17, 2013 by Derrick Klotz

I'm using an 'HC908JK3 in a noisy automotive ignition environment. Have several variations on a theme over half a dozen different boards, the relevant code being virtually identical except for I/O differences to help board layout. One board in particular has a habit of acting up for some customers although I have not been able to reproduce it on the bench. My recent post regarding what to do with unbonded input pins was a big help in getting on top of this problem, so thanks to all that helped.

 

Anyway, my code uses no interrupts so I want to put a trap in the vector area so if a spurious interrupt does occur it can recover gracefully. What is the best way of doing this? I have all interrupts disabled but I want to go both belt and braces.

 

               ORG     $FFDE

               RTI

               ORG     $FFE0

               RTI

               etc,

 

OR

 

               ORG     $FFDE

               FDB     START

               ORG     $FFE0

               FDB     START

               etc

 

"START" is the very top of the listing, the reset vector.

 

Regards,

Graham

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