PCA
所涉及的寄存器
CCON
CMOD
CCAPM0
CCAPM1
CL_CH_CCAPnL_CCAPnH
PCA 模块工作模式设定
PCA_PWM0_PCA_PWM1
PCA_PWM 结构图
PCA定时器 结构图
注意，与Timerx不同，CCAPMnH/CCAPMnL需要每次计数给一个步进才能正常计数(从下往上计数)
例子
PCA_PWM0_PWM1
PCA_PWM.h
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| #ifndef __PCA_PWM_H
#define __PCA_PWM_H
#include <reg52.h>
sfr CCON = 0xd8;
sfr CMOD = 0xd9;
sfr CCAPM0 = 0xda;
sfr CCAPM1 = 0xdb;
sfr CL = 0xe9;
sfr CH = 0xf9;
sfr CCAP0L = 0xea;
sfr CCAP0H = 0xfa;
sfr CCAP1L = 0xeb;
sfr CCAP1H = 0xfb;
sfr PCA_PWM0 = 0xe2;
sfr PCA_PWM1 = 0xf3;
sfr AUXR = 0x8e;
sfr AUXR1 = 0xa2;
sbit CCF0 = CCON^0;
sbit CCF = CCON^1;
sbit CR = CCON^6;
sbit CF = CCON^7;
void PCA_PWM_Init();
#endif
|
PCA_PWM.c
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| #include "PCA_PWM.h"
void PCA_PWM_Init()
{
TR0 = 1; // Init Timer0 1t
TMOD = 0x02;
TH0 = TL0 = 256 - 4 ; // 1/(10K*256) = TIMS*(1/11059200) TIMS = 4.3
AUXR = 0x80;
CCON = 0; //clear
CL = CH = 0; //clear
CMOD = 0x04; //set PCA timer clock source as Timero
CCAP0H = CCAP0L = 0x80; //256/2 = 128 = 0x80 50%duty cycle square wave
CCAPM0 = 0x42 ; //work in 8 bit PWM0 mode no PCA interrupt
CCAP1H = CCAP1L = 0x40; //256/4 = 64 = 0x40 75%duty cycle square wave
CCAPM1 = 0x42 ; //work in 8 bit PWM1 mode
CR = 1; //enable PCA
}
|
main.c
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| #include "main.h"
void main()
{
PCA_PWM_Init(); // P13 PWM0 p14 pwm1
while(1);
}
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main.h
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| #ifndef __MAIN_H
#define __MAIN_H
#include <reg52.h>
#include "PCA_PWM.h"
#endif
|
PCA_Timer
PCA_Timer.c
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| #include <PCA_Timer.h>
unsigned int count ;
unsigned int value ;
void PCA_Timer_Init()
{
CCON = CMOD = 0; //clear
CMOD =0x08; //PCA Timer source from Systemclock/1 1/11059200HZ
CL = CH = 0; //clear
CCAPM0 = 0x49 ; //PCA work in 16 bit Timer enable PCA interrupt
CCAP0L = value ;
CCAP0H = value>>8;
CR = 1; //start PCA
EA = 1; //enable main interrupt
count = 0;
}
void PCA_Interrupt() interrupt 7
{
CCF0 = 0; //clear interrupt flag
CCAP0L = value; //reload
CCAP0H = value>>8;
value+=TIMS; //add stepping!
count++;
if(count>=1000)
{
count = 0;
LED = !LED; //1s
}
}
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PCA_Timer.h
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| #ifndef __PCA_TIMER_H
#define __PCA_TIMER_H
#include <reg52.h>
#define TIMS (11059200L/1000)
sfr CCON = 0xd8;
sfr CMOD = 0xd9;
sfr CCAPM0 = 0xda;
sfr CCAPM1 = 0xdb;
sfr CL = 0xe9;
sfr CH = 0xf9;
sfr CCAP0L = 0xea;
sfr CCAP0H = 0xfa;
sfr CCAP1L = 0xeb;
sfr CCAP1H = 0xfb;
sfr PCA_PWM0 = 0xe2;
sfr PCA_PWM1 = 0xf3;
sfr AUXR = 0x8e;
sfr AUXR1 = 0xa2;
sbit CCF0 = CCON^0;
sbit CCF = CCON^1;
sbit CR = CCON^6;
sbit CF = CCON^7;
sbit LED = P3^0;
void PCA_Timer_Init();
#endif
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main.c
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| #include "main.h"
void main()
{
PCA_Timer_Init();
while(1);
}
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main.h
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| #ifndef __MAIN_H
#define __MAIN_H
#include <reg52.h>
#include "PCA_Timer.h"
#endif
|
