www.pudn.com > 8253-2.rar > 8253-1.ASM

;定时器8253的例子:利用BIOS调用INT1AH/00H取得计时单位(55MS),在屏幕上每个;以5秒间隔从1到8显示 
DATA   SEGMENT 
       SED  DB '0' 
DATA   ENDS   
STACK  SEGMENT STACK 
       DW  64  DUP(0) 
STACK  ENDS 
 
CODE   SEGMENT 
       ASSUME CS:CODE,SS:STACK,DS:DATA 
 
START:   MOV   AX,DATA 
         MOV   DS,AX 
   GOT:  MOV   AH,00H 
         INT   1AH               ;BIOS调用,取计时单位(55ms),在DX 
         ADD   DX,91             ;5s/55ms=5000ms/55ms=91  
         MOV   BX,DX 
   LOP:  MOV   AH,00H 
         INT   1AH 
         CMP   DX,BX 
         JNZ   LOP 
         MOV   DL,SED 
         MOV   AH,02H            ;DOS调用,显示一个字符 
         INT   21H 
         INC   SED 
         CMP   SED,'9' 
         JNZ   GOT  
         MOV   SED,'0' 
         MOV   AH,4CH 
         INT   21H            
CODE  ENDS 
      END   START