.include "8535def.inc"
RESET:   ldi r16,low(ramend)    ;棧指針置初值
         out spl,r16
         ldi r16,high(ramend)
         out sph,r16
         ldi r16,$ff            ;定義C口為輸出
         out ddrc,r16
         ldi r16,$01            ;定義PD0為輸出，PD2為輸入
         out ddrd,r16
         sbi portd,0            ;先使PD0輸出為高
         ldi xh,$01             ;X指向打印緩沖區(qū)首址
         ldi xl,$00
         ldi r25,18             ;要打印的字符數(shù)
loop:    ld r24,x+              ;向打印機(jī)數(shù)據(jù)口送一個(gè)字符
         out portc,r24
         cbi portd,0            ;發(fā)選通脈沖（/STB）
         rcall t1us
         sbi portd,0
         rcall t1us             ;延時(shí)3us
         rcall t1us 
         rcall t1us
loop1:   sbic pind,2            ;等待忙線變低
         rjmp loop1
         dec r25                ;字節(jié)數(shù)是否發(fā)完
         brne loop              ;沒發(fā)完再發(fā)下一個(gè)
here:    rjmp here
t1us:    nop
         ret