定时器查询法和定时器中断法实现LED闪烁

1、定时器查询法实现LED闪烁

;2013/4/23
;延时1s闪烁org   0000h                ajmp  startorg   30h
start:mov   r0,#20			mov   p0,#0ffh		;关灯mov   TMOD,#00000001Bmov   TH0,#3CH        ;50ms定时mov   TL0,#0B0Hsetb  TR0
loop: jbc   TF0,next         ;TF1为1时转移ljmp  loop
next: mov   TH0,#3CHmov   TL0,#0B0H	djnz  r0,loop         ;r0减1不为0跳转cpl   p0.0mov   r0,#20ljmp  loopend

2、定时器中断实现LED闪烁

;2013/4/24org 0000hajmp 	startorg 000bh          ;定时器0的中断向量地址ajmp 	time0org 30h
start:mov  p0,#0ffhmov  TMOD,#00000001Bmov  TH0,#3Chmov  TL0,#0b0hsetb EAsetb ET0setb TR0
loop: ajmp loop
time0:cpl  p0.0mov  TH0,#3Chmov  TL0,#0b0hreti               ;中断返回end