学C语言第三天

用PWM引脚进行配置然后进行LED呼吸灯的控制

#include "stc8g.h"
#include "intrins.h"
#define PWM0C (*(unsigned int volatile xdata *)0xFF00)
#define PWM05T1 (*(unsigned int volatile xdata *)0xFF38)
#define PWM05T2 (*(unsigned int volatile xdata *)0xFF3A)
void PWM0_Routine(void) interrupt 22
{
static unsigned int val;
static bit dir = 1;
if(PWMCFG01 & 0X08)

{
PWMCFG01&=~0x08;
if(dir)
{
val++;
if(val>=0x1000) dir = 0;;
}
else
{
val--;
if(val<=1) dir = 1;
}
PWM05T2 = val;
}

}

void main()
{
P0M0 = 0X00;
P0M1 = 0X00;

P_SW2 |= 0X80; //允许访问特殊功能寄存器
PWM0CKS = 0X00; //选择系统时钟做为PWM0时钟 不分频
PWMSET = 0X01; //打开PWM0模块
PWM05CR = 0X80; //设置P0.5引脚为PWM引脚 初始电平为低电平
PWM0C = 0x1000;//周期
PWM05T1 = 0X0000;//变低电平
PWM05T2 = 0X0001;//变高电平
PWMCFG01 = 0X05;//打开PWM0定时器 允许归0中断

EA = 1;


while(1)

 

{

}
}