Re: [avr-gcc-list] Interrupt prologue and epilogue

[Joerg Wunsch]

Simon Han <address@hidden> wrote:

>       Is there any documentation about how interrupt prologue and
> epilogue are implemented?  I am mainly interested in what registers
> need to be save and why.

In an interrupt context: everything you change in your ISR needs to be
saved.  If your instructions modify SREG, that needs to be saved as
well.  You are not even allowed to make the assumption that r1
contained a literal 0 at interrupt time.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)