资 源 简 介
8253的初始化程序举例:
例1：选择2号计数器，工作在3方式，计数初值为533H（2个字节），采用二进制计数。其初始化程序段为
MOV DX，307H ；命令口
MOV AL，10110110B ；2号计数器的初始化命 令字
OUT DX，AL ；写入命令寄存器
MOV DX，306H ；2号计数器数据口
MOV AX，533H ；计数初值
OUT DX，AL ；选送低字节到2号计数器
MOV AL，AH ；取高字节送AL
OUT DX，AL ；后送高字节到2号计数器
-8253 initialization procedures examples : Example 1 : Select counters on the 2nd, in three ways. Counting for the initial 533H (2 bytes), a binary counting. Initialization of its procedures for MOV DX, 307H; I ordered MOV AL, 10110110B; on the 2nd Counter initialize command word OUT DX, AL; write commands Register MOV DX, 306H; data on the 2nd Counter I MOV AX, 533H; Counting initial OUT DX, AL; low-byte sent to the 2nd Counter MOV AL, AH; With a high-byte send AL OUT DX, AL; evacuations high byte counter to the 2nd
