学习C8051F340单片机中，如何配置P4端口，能否简单写个配置端口的程序？

Posted 2023-05-07

参考技术A void Port_IO_Init()

// P0.0 - Unassigned, Open-Drain, Digital
// P0.1 - Unassigned, Open-Drain, Digital
// P0.2 - Unassigned, Open-Drain, Digital
// P0.3 - Unassigned, Open-Drain, Digital
// P0.4 - Unassigned, Open-Drain, Digital
// P0.5 - Unassigned, Open-Drain, Digital
// P0.6 - Unassigned, Open-Drain, Digital
// P0.7 - Unassigned, Open-Drain, Digital

// P1.0 - Unassigned, Open-Drain, Digital
// P1.1 - Unassigned, Open-Drain, Digital
// P1.2 - Unassigned, Open-Drain, Digital
// P1.3 - Unassigned, Open-Drain, Digital
// P1.4 - Unassigned, Open-Drain, Digital
// P1.5 - Unassigned, Open-Drain, Digital
// P1.6 - Unassigned, Open-Drain, Digital
// P1.7 - Unassigned, Open-Drain, Digital

// P2.0 - Unassigned, Open-Drain, Digital
// P2.1 - Unassigned, Open-Drain, Digital
// P2.2 - Unassigned, Open-Drain, Digital
// P2.3 - Unassigned, Open-Drain, Digital
// P2.4 - Unassigned, Open-Drain, Digital
// P2.5 - Unassigned, Open-Drain, Digital
// P2.6 - Unassigned, Open-Drain, Digital
// P2.7 - Unassigned, Open-Drain, Digital

// P3.0 - Unassigned, Open-Drain, Digital
// P3.1 - Unassigned, Open-Drain, Digital
// P3.2 - Unassigned, Open-Drain, Digital
// P3.3 - Unassigned, Open-Drain, Digital
// P3.4 - Unassigned, Open-Drain, Digital
// P3.5 - Unassigned, Open-Drain, Digital
// P3.6 - Unassigned, Open-Drain, Digital
// P3.7 - Unassigned, Open-Drain, Digital

P4MDOUT = 0xFF;
XBR1 = 0xC0;


P4口推挽输出，弱上拉 参考技术B P4口与其余口的配置方式一样的， 只不过其不能位操作。

如何利用单片机控制一颗LED 灯闪烁

    点亮一颗LED灯是我们学习单片机入门的开始，今天目标的是利用单片机控制LED灯闪烁，下图是protues 仿真电路图，图中单片机左边为系统的时钟电路和复位电路，右边是LED 灯电路。

 下面是实现程序：首先定义了led=P2^0口为输出端口，用来控制LED 灯，LED 灯的阴极是与单片机连接的，因此引脚必须输出低电平才能点亮LED 灯。在主函数main 的while循环体中，我们先把输出引脚设置为低电平，即led=0;点亮LED 灯,然后调用延时函数delay()；对亮灯进行延时，然后再把输出引脚置为高电平，即led=1;熄灭LED灯，调用延时函数对熄灯延时。由于while语句的条件为１，即判断条件永远为真，所以程序会不停的循环执行while语句，这样就可以实现LED灯的闪烁。

#include<reg51.h>//包含头文件
sbit led=P2^0;//定义引脚，用来连接LED灯
void delay()//延时函数，实现对LED 灯的亮灭延时控制
{
unsigned int i,j;
for(i=0;i<1000;i++)
for(j=0;j<5;j++);
}
void main(void)
{
while(1){
led=0;//点亮LED 灯
delay();//延时
led=1;//熄灭LED灯
delay();//延时
}
}