8253/8254的应用

    以下是用8086／8088汇编语言编写的主程序以及中断服务程序的框架结构。
    STACK              SEGMENT   PARA   STACK   ’STACK’    }
    STAPN              DW 512 DUP(?)
    TOP                   EQ $- STAPN
    STACK             ENDS 
                         ；这里堆栈段的定义仅仅是形式(否则汇编连接时会出现警告错误)，
                          ；而实际使用的是当前栈，即操作系统或高级语言使用的栈
    CODE                SEGMENT    PARA    PUBLIC   ’CODE’
                                ……… ；数据区(用DB、DW伪指令安排，这里是数据、代码共用一个段)
    START                 PROC FAR
                                 ASSUME CS：CODE     
                                 PUSH DS
                                  MOV AX，0
                                 PUSH AX
                                  ASSUME DS：CODE
                                   MOV AX．CS
                                   MOV DS．AX
                                   MOV DX，153H    ；初始化计数器0为方波发生器
                                   MOV AL．36H
                                   OUT DX．AL
                                   MOV DX．150H
                                   MOV BX．32
                                   MOV AL．BL 
                                   OUT DX．AL
                                   MOV AL．BH      
                                   OUT DX．AL
                                    MOV DX，153H    ；初始化计数器1为方波发生器
                                   MOV AL，76H
                                     OUT DX，AL
                                   MOV DX，151H 
                                      MOV BX，2304
                                      MOV AL，BL 
                                     OUT DX，AL
                                     MOV AL，BH
                                    OUT DX，AL
                                    MOV DX，OFFSET INTSERV；调用DOS功能(25H)设置类型号ODH的中断向量

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本文关键字：暂无联系方式元器件特点及应用，元器件介绍 - 元器件特点及应用