STC15单片机利用PCA在扩展外部中断和定时器以及脉宽测量的应用示例
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STC单片机利用PCA在扩展外部中断和定时器以及脉宽测量的应用示例
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相关篇《STC15系列CCP/PWM/PCA介绍》
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STC15W408AS开发板
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STC-ISP设置选项
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用CCP/PCA功能扩展外部中断的测试程序
- 实验现象说明： 当P1.1口的电平被拉低是产生中断，让P1.0 引脚口上的电平发生反转。
//用CCP/PCA功能扩展外部中断的测试程序
//单片机型号：STC15W408AS
//工作频率一般为11.0592MHz
#include "reg51.h"
#include "intrins.h"
typedef unsigned char BYTE;
typedef unsigned int WORD;
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
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 PCAPWM0 = 0xf2;
sfr PCAPWM1 = 0xf3;
sbit PCA_LED = P1^0; //PCA测试LED
void PCA_isr() interrupt 7
CCF0 = 0; //清中断标志
PCA_LED = !PCA_LED; //测试LED取反
void main()
P0M0 = 0x00;
P0M1 = 0x00;
P1M0 = 0x00;
P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P4M0 = 0x00;
P4M1 = 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)
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=1 CCP_S1=0
// ACC |= CCP_S0; //(P3.4/ECI_2, P3.5/CCP0_2, P3.6/CCP1_2, P3.7/CCP2_2)
// P_SW1 = ACC;
//
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=0 CCP_S1=1
// ACC |= CCP_S1; //(P2.4/ECI_3, P2.5/CCP0_3, P2.6/CCP1_3, P2.7/CCP2_3)
// P_SW1 = ACC;
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 = 0x00; //设置PCA时钟源
//禁止PCA定时器溢出中断
CCAPM0 = 0x11; //PCA模块0为下降沿触发0001 0001
// CCAPM0 = 0x21; //PCA模块0为上升沿沿触发0010 0001
// CCAPM0 = 0x31; //PCA模块0为上升沿/下降沿触发0011 0001
CR = 1; //PCA定时器开始工作
EA = 1;
while (1);
用CCP/PCA功能实现16位定时器的测试程序
- 实验现象;接在P1.0口上的led灯，每隔一秒钟闪烁一次。
//用CCP/PCA功能实现16位定时器的测试程序
//单片机型号：STC15W408AS
//工作频率一般为11.0592MHz
#include "reg51.h"
#include "intrins.h"
#define FOSC 11059200L
#define T100Hz (FOSC / 12 / 100)
typedef unsigned char BYTE;
typedef unsigned int WORD;
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
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 PCAPWM0 = 0xf2;
sfr PCAPWM1 = 0xf3;
sbit PCA_LED = P1^0; //PCA测试LED
BYTE cnt;
WORD value;
void PCA_isr() interrupt 7 //PCA中断
CCF0 = 0; //清中断标志
CCAP0L = value;
CCAP0H = value >> 8; //更新比较值
value += T100Hz; //(11059200 / 12 / 100) = 96
if (cnt-- == 0)
cnt = 100; //记数100次
PCA_LED = !PCA_LED; //每秒闪烁一次
void main()
P0M0 = 0x00;
P0M1 = 0x00;
P1M0 = 0x00;
P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P4M0 = 0x00;
P4M1 = 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)
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=1 CCP_S1=0
// ACC |= CCP_S0; //(P3.4/ECI_2, P3.5/CCP0_2, P3.6/CCP1_2, P3.7/CCP2_2)
// P_SW1 = ACC;
//
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=0 CCP_S1=1
// ACC |= CCP_S1; //(P2.4/ECI_3, P2.5/CCP0_3, P2.6/CCP1_3, P2.7/CCP2_3)
// P_SW1 = ACC;
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 = 0x00; //设置PCA时钟源，SYSclk/12
//禁止PCA定时器溢出中断
value = T100Hz;
CCAP0L = value;
CCAP0H = value >> 8; //初始化PCA模块0
value += T100Hz;
CCAPM0 = 0x49; //PCA模块0为16位定时器模式0100 1001
CR = 1; //PCA定时器开始工作
EA = 1;
cnt = 0;
while (1);
用CCP/PCA的16位捕获模式测脉冲宽度的程序
该示例程序没有验证成功，在外部输入pwm到引脚上，串口并没看到数据。
//用CCP/PCA的16位捕获模式测脉冲宽度的程序
//单片机型号：STC15W408AS
//工作频率一般为11.0592MHz
#include "reg51.h"
#include "intrins.h"
#include <stdio.h> // 为使用KEIL自带的库函数printf而加入
#define FOSC 11059200L
typedef unsigned char BYTE;
typedef unsigned int WORD;
typedef unsigned long DWORD;
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
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
sfr AUXR = 0x8E; //0000,0000 辅助寄存器
sfr T2H = 0xD6; //0000,0000 T2高字节
sfr T2L = 0xD7; //0000,0000 T2低字节
sbit EPCA = IE^6; //PCA中断允许位
BYTE cnt; //存储PCA计时溢出次数
DWORD count0; //记录上一次的捕获值
DWORD count1; //记录本次的捕获值
DWORD length; //存储信号的时间长度(count1 - count0)
/*------------------------------------------------
串口初始化函数，波特率9600
------------------------------------------------*/
void UART_init(void)
SCON = 0x50; //8位数据,可变波特率
AUXR |= 0x01; //串口1选择定时器2为波特率发生器
AUXR &= 0xFB; //定时器时钟12T模式
T2L = 0xE8; //设置定时初始值
T2H = 0xFF; //设置定时初始值
AUXR |= 0x10; //定时器2开始计时
TI=1; // 很关键，使用printf函数时必须有此命令
ES = 1; //开启串口中断
EA=1; //开启总中断
//UART1 发送串口数据
void UART1_SendData(char dat)
ES=0; //关串口中断
SBUF=dat;
while(TI!=1); //等待发送成功
TI=0; //清除发送中断标志
ES=1; //开串口中断
//UART1 发送字符串reentrant
//void UART1_SendString(char *s)
//
// while(*s)//检测字符串结束符
//
// UART1_SendData(*s++);//发送当前字符
//
//
//重写putchar函数
char putchar(char c)
UART1_SendData(c);
return c;
void main()
P0M1 = 0x03;
P0M0 = 0x00; //P0(双双双双双双高高)
// P1M0 = 0x00;
// P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P4M0 = 0x00;
P4M1 = 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)
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=1 CCP_S1=0
// ACC |= CCP_S0; //(P3.4/ECI_2, P3.5/CCP0_2, P3.6/CCP1_2, P3.7/CCP2_2)
// P_SW1 = ACC;
//
// ACC = P_SW1;
// ACC &= ~(CCP_S0 | CCP_S1); //CCP_S0=0 CCP_S1=1
// ACC |= CCP_S1; //(P2.4/ECI_3, P2.5/CCP0_3, P2.6/CCP1_3, P2.7/CCP2_3)
// P_SW1 = ACC;
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;
CCAP1L = 0;
CCAP1H = 0;
CMOD = 0x09; //设置PCA时钟源为系统时钟,且使能PCA计时溢出中断
//CMOD = 0x01; //12
// CCAPM0 = 0x21; //PCA模块0为16位捕获模式(上升沿捕获,可测从高电平开始的整个周期),且产生捕获中断
// CCAPM0 = 0x11; //PCA模块0为16位捕获模式(下降沿捕获,可测从低电平开始的整个周期),且产生捕获中断
CCAPM1 = 0x31; //PCA模块0为16位捕获模式(上升沿/下降沿捕获,可测高电平或者低电平宽度),且产生捕获中断
CR = 1; //PCA定时器开始工作
EA = 1;
cnt = 0;
count0 = 0;
count1 = 0;
UART_init();
printf("STC15W408AS \\n");
printf("TRG!!!\\n");
while (1)
if(length > 0)
printf("Pulse_length: %lu\\n",length);
length = 0 ;
void PCA_isr() interrupt 7
if (CF)
CF = 0;
cnt++; //PCA计时溢出次数+1
if (CCF1)
CCF1 = 0;
count0 = count1; //备份上一次的捕获值
((BYTE *)&count1)[3] = CCAP1L; //保存本次的捕获值
((BYTE *)&count1)[2] = CCAP1H;
((BYTE *)&count1)[1] = cnt;
((BYTE *)&count1)[0] = 0;
length = count1 - count0; //计算两次捕获的差值,即得到时间长度
CCP/PCA输出PWM(6位+7位+8位)的测试程序
通过逻辑分析仪，本示例代码，值采集到了P1.0和P37引脚上的PWM波形，P1.1并没有产生PWM波。
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采集到P10引脚的占空比：约75%
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采集到P37引脚的PWM占空比：50%
//CCP/PCA输出PWM(6位+7位+8位)的测试程序
#include "reg51.h"
#include "intrins.h"
#define FOSC 11059200L
typedef unsigned char BYTE;
typedef unsigned int WORD;
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
sfr P5M1 = 0xC9;
sfr P5M0 = 0xCA;
sfr P6M1 = 0xCB;
sfr P6M0 = 0xCC;
sfr P7M1 = 0xE1;
sfr P7M0 = 0xE2;
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()
P0M0 = 0x00;
P0M1 = 0x00;
P1M0 = 0x00;
P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00STC15系列CCP/PWM/PCA介绍
11.STC15W408AS单片机CCP/PCA/PWM应用
11.STC15W408AS单片机CCP/PCA/PWM应用
11.STC15W408AS单片机CCP/PCA/PWM应用