AVR-Chat

--- In AVR-Chat@yahoogroups.com, "Paul Maddox" <P.Maddox@s...> wrote:
> Leon,
> 
> Thanks, I hadn't spotted that in the instruction set.
> Just looking at IJMP, it may be simpler to use, no pushing/pulling 
from the 
> stack and its 1 less clock cycle (speed is king)...

I've just written a simple jump table program using ICALL:

  .include "tn2313def.inc"

     .def	temp=r16


     .cseg
	 .org	0
	 rjmp	reset

reset:
	ldi		temp,low(RAMEND)
	out		spl,temp
	ldi		temp,$03


loop:
	rol		temp
	ldi		zl,low(jump_table)
	ldi		zh,high(jump_table)
	add		zl,temp
	icall
	rjmp	loop


jump_table:
	rcall	zero
	ret
	rcall	one
	ret
	rcall	two
	ret
	rcall	three
	ret

zero:
	ret

one:
	ret

two:
	ret

three:
	ret


Change temp within the loop using the simulator to check that it 
works.

Leon