Interrupt with NOSAVE option

FanieTerblanche · Joined: 20 Apr 2006 Posts: 26

Hi All,

I would like to know how to determine what registers to save when i am using the NOSAVE option for INT0.

Thanks in advance.

Vilko · Posted: Tue Sep 19, 2006 9:01 am Post subject: I usualy do this way

It depends on your interrupt subroutine, what register are to be saved: those, used in the subroutine.

If the subroutine is in Basic, i usually do this way:
I compile subroutine extra, disasseble it and look at assemble list, which tells me, what reagisters are used.

I usually use NOSAVE option only with very simple ISR like
INCR variable or Set bitvariable
return

and variable must be one byte.

Yes, it is thrue, on 128 Bytes of RAM, Save takes about 20 bytes fo Stack.