8253/8254的应用

                                    MOV AX，CS
                                     NOV DS，AX    ；入口参数：DS：段地址
                                     MOV AL，0DH    ；DX：段内偏移量
                                     MOV AH，25H    ；AL：中断类型号
                                     INT 21H
                                     MOV DX，1000H    ；调用DOS功能(31H)程序驻留退出
                                     MOV AH，31H      ；保留地址空间为1000H*16=64 KB
                                     INT 1H
                                      ；使用汇编语言编写主程序时，中断服务程序不必驻留
INTSERV                     PROC FAR           ；中断服务程序应是远调用
                                      PUSH  DS           ；保护现场(根据中断服务程序使用寄
                                       PUSH AX            ；存器的情况有选择地入栈)
                                       PUSH BX
                                        PUSH CX
                                       PUSH DX
                                       PUSH SI
                                       PUSH DI
                                        MOV AX，CS    ；DS指向中断服务程序数据区
                                       MOV DS，AX
                                       STI                        ；开中断
                                       ……                      ；具体的中断服务
                                       MOV AL，20H    ；发中断结束命令EOI
                                       OUT 20H，AL 
                                         POP DI    ；恢复现场
                                         POP SI
                                         POP DX
                                          POP CX 
                                          POP BX
                                          POP AX 

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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