; *****************************************************
; * To pass a parameter to a macro is easy to program *
; * Demonstrates the use of macros with the ATMEL     *
; * assembler, just a test program for use with the   *
; * ATMEL STK200 board, (C) 2000 Gerhard Schmidt      *
; * Report bugs to info@avr-asm-tutorial.net          *
; *****************************************************
;
.NOLIST
.INCLUDE "C:\avrtools\appnotes\8515def.inc"
.LIST
;
; Used registers
;
.DEF mpr=R16 ; a multi purpose register
;
; The following is the macro which includes a label
; within that macro (mjmp) and the value for the
; register is handed over with the first parameter
; referenced by @0.
;
.MACRO TestMacro
	ldi	mpr,@0 ; Set mpr-value to first parameter
	inc	mpr ; Add one
	brne	mjmp ; If no overflow skip the next
	rjmp	ovf ; Jump if overflow occurs
mjmp:
.ENDMACRO
;
.LISTMAC
;
; Start of main program
;
	ldi	mpr,0xFF ; Set PortB (LEDs) to be output
	out	DDRB,mpr ; to Data Direction Register
;
	ldi	mpr,0xFE ; Set the register to 254
; Here comes the macro: 0xFF is passed to it, then INCed
; and, as it is zero, jumps to the label ovf
;
	testmacro(0xff) ; Insert the macro here
;
; As there should have been an overflow during the last INC
; the following code should not be reached. If executed,
; it would result in all LEDs on.
; 
outp:
	out	PORTB,mpr
loop:
	rjmp	loop ; and end the program in a loop
;
; The overflow should occur and this code will be executed
;
ovf:
	ldi	mpr,0xFF ; Blank all LEDs
	out	PORTB,mpr ; at Port B
	rjmp	loop ; Jump to indefinite loop
;
; After execution all the LEDs PB.0 to PB.7 should be off.