;*****************************************************************
;* FLEDS.ASM:	Let 2 or 8 LEDs walk on PORTB using data from the
;*		internal Flash memory of the AT90S2313.
;*
;* RES can be reached by email: http://www.attiny.com/contact.htm
;* Website: http://www.attiny.com
;* 
;* Version	:1.0
;* Data		:27-Oct-2002
;* Target MCU	:AT90S2313@4MHz
;*****************************************************************

.include "2313def.inc" 


	rjmp	RESET			;reset handle


;* Delay

;* Register variables

	.def	T1	= r1		;lower registers
	.def	T2	= r2
	.def	temp	= r16		;higher register

;* Defines

;* Code

longDelay:
	clr	T1			;T1 used as delay 2nd count
	clr	T2			;T2 used as delay 3d count
delay1:	dec	T2
	brne	delay1
	dec	T1
	brne	delay1
	dec	temp			;temp must be preset as 
	brne	delay1			;  delay master count
	ret




;* Walk 8 LEDs on PORTB back and forth, reading data from Flash memory

;* Register variables

	.def	LEDdata	= r0		;Flash memory load register

;* Code

RESET:	ldi	temp, RAMEND		;point stack in RAM
	out	SPL, temp
	ser	temp
	out	DDRB, temp		;set PORTB i/o's as outputs
init:	ldi	ZL, LOW(tabel*2)	;set Low memory pointer
	ldi	ZH, HIGH(tabel*2)	;set High memory pointer

;* Main program

loop:	lpm				;load data from Flash into r0
	out	PORTB, LEDdata		;set data on PORTB
	ldi	temp, 10
	rcall	longDelay		;wait 10 x 49.3 msec = approx. 0.5 sec
	inc	ZL
	lpm				;check data at this moment
	mov	temp, LEDdata
	cpi	temp, '#'		;if # reached in memory,
	breq	init			; -> restart + reset memory
	rjmp	loop			;flash or walk LEDs





;* Data
;* 8 + 8 bits data sits in Flash like this
;* set '#' at end for walking LEDs

tabel:	.db 0b00000001,0b00000010	;data 0, 1
	.db '#'				;set end position
	.db 0b00000100,0b00001000	;data 2, 3 
	.db 0b00010000,0b00100000	;data 4, 5
 	.db 0b01000000,0b10000000	;data 6, 7