display.asm

AVR-AT90S8535,HD8279,等开发的洁净空调专用DDC系统,包括AD/DA,PID计算等.

.include"8535def.inc"
.org	0x00
	rjmp	RESET 
.org	0x020
reset:	ldi	r16,$ff
	out	ddrd,r16
	out	ddrb,r16
	ldi	r16,$78
	out	portd,r16
	cbi	portd,6	;8279写控制寄存器
	cbi	portd,4
	ldi	r16,$d1
	out	portb,r16
	nop
	sbi	portd,4
	ldi	r20,$56	
	rcall	Delay
	cbi	portd,4
	ldi	r16,$0
	out	portb,r16
	nop
	sbi	portd,4
	nop
	cbi	portd,4
	ldi	r16,$22
	out	portb,r16
	sbi	portd,4
	nop
dip:	
	sbi	portd,5	
	cbi	portd,4
	ldi	r16,$90
	out	portb,r16
	nop
	sbi	portd,4
	cbi	portd,5	
	cbi	portd,4
	ldi	r16,$fe
	out	portb,r16
	
	
	ldi	r20,0X56	
	rcall	Delay
	rjmp	dip
	
delay:  push    r20         ;2t延时子程序
l0:     push   r20          ;2t
l1:     push    r20         ;2t
l2:     push    r20         ;2t
l3:     dec     r20         ;1t
        brne    l3          ;1t/2t
        pop    r20          ;2t
        dec    r20         ;1t 
        brne    l2          ;1t/2t
        pop    r20          ;2t
        dec    r20          ;1t 
        brne    l1          ;1t/2t
        pop     r20         ;2t
        dec     r20         ;1t 
        brne    l0          ;1T/2T
        pop     r20         ;2t
        ret                 ;4t