In SX Microcontrollers, SX/B Compiler and SX-Key Tool, sammishal wrote:

MadMax (I guess you are Auzie ???)

If you use JMP and never return to the RETI command you have effectively cancelled the
interrupt capacity of the SX. I.E. you end up with the SX doing one interrupt and after it enters
the ISR and you never execute an RTI (or RETIW) you end up having the SX act as a normal
CPU without any more interrupts. Since upon entry into the ISR the SX disables any further Interrupts.
The SX enables further interrupts as part of executing the RETI/W instruction.

If all you want is the SX to respond to one interrupt once only and then do something and you do not
need to ever do the same thing again (that is in response to whatever caused the Interrupt), then use 
JMP by all means. 

However, that is not why (or how) Interrupts are used. You should always (strictly speaking) return 
eventually from the ISR with a RETI/W. 

I think that you are not quite grasping the use of interrupts. A very good explanation of what to do 
is Gunther's Book.

Why not have the ISR set some flags and then issue an RTI/W and then your program can upon these flags
and then reset them so that the next invocation of the ISR will be able to set them again to indicate
the occurence of the event that you are monitering.

Regards

Samuel

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