#include "reg51.h" // 官网例程，可以参考一下。
#include "intrins.h"
#define FOSC 11059200L
typedef unsigned char BYTE;
typedef unsigned int WORD;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P5M1 = 0xC9;
sfr P5M0 = 0xCA;
sfr P_SW1 = 0xA2; //外设功能切换寄存器1
#define CCP_S0 0x10 //P_SW1.4
#define CCP_S1 0x20 //P_SW1.5
sfr CCON = 0xD8; //PCA控制寄存器
sbit CCF0 = CCON^0; //PCA模块0中断标志
sbit CCF1 = CCON^1; //PCA模块1中断标志
sbit CR = CCON^6; //PCA定时器运行控制位
sbit CF = CCON^7; //PCA定时器溢出标志
sfr CMOD = 0xD9; //PCA模式寄存器
sfr CL = 0xE9; //PCA定时器低字节
sfr CH = 0xF9; //PCA定时器高字节
sfr CCAPM0 = 0xDA; //PCA模块0模式寄存器
sfr CCAP0L = 0xEA; //PCA模块0捕获寄存器 LOW
sfr CCAP0H = 0xFA; //PCA模块0捕获寄存器 HIGH
sfr CCAPM1 = 0xDB; //PCA模块1模式寄存器
sfr CCAP1L = 0xEB; //PCA模块1捕获寄存器 LOW
sfr CCAP1H = 0xFB; //PCA模块1捕获寄存器 HIGH
sfr CCAPM2 = 0xDC; //PCA模块2模式寄存器
sfr CCAP2L = 0xEC; //PCA模块2捕获寄存器 LOW
sfr CCAP2H = 0xFC; //PCA模块2捕获寄存器 HIGH
sfr PCA_PWM0 = 0xf2; //PCA模块0的PWM寄存器
sfr PCA_PWM1 = 0xf3; //PCA模块1的PWM寄存器
sfr PCA_PWM2 = 0xf4; //PCA模块2的PWM寄存器
void main()
{
P1M0 = 0x00;
P1M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P5M0 = 0x00;
P5M1 = 0x00;
ACC = P_SW1;
ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=0 CCP_S1=0
P_SW1 = ACC; //(P1.2/ECI, P1.1/CCP0, P1.0/CCP1, P3.7/CCP2)
CCON = 0; //初始化PCA控制寄存器
//PCA定时器停止
//清除CF标志
//清除模块中断标志
CL = 0; //复位PCA寄存器
CH = 0;
CMOD = 0x02; //设置PCA时钟源
//禁止PCA定时器溢出中断
PCA_PWM0 = 0x00; //PCA模块0工作于8位PWM
CCAP0H = CCAP0L = 0x20; //PWM0的占空比为87.5% ((100H-20H)/100H)
CCAPM0 = 0x42; //PCA模块0为8位PWM模式
PCA_PWM1 = 0x40; //PCA模块1工作于7位PWM
CCAP1H = CCAP1L = 0x20; //PWM1的占空比为75% ((80H-20H)/80H)
CCAPM1 = 0x42; //PCA模块1为7位PWM模式
PCA_PWM2 = 0x80; //PCA模块2工作于6位PWM
CCAP2H = CCAP2L = 0x20; //PWM2的占空比为50% ((40H-20H)/40H)
CCAPM2 = 0x42; //PCA模块2为6位PWM模式
CR = 1; //PCA定时器开始工作
while (1);
}
追问你好手册上的我也看了，但是没有看明白哪个是控制占空比的？还有哪个引脚是输出
？