配置PCA的一点总结12单片机

先看代码

#include "stc12.h"

unsigned int Last_Capture_Data=0;
unsigned int New_Capture_Data=0;
unsigned int g_Period=0;
unsigned int g_Frequency=0;
unsigned char str1[12];
unsigned char str2[12];
bit Capture_over = 0;

sbit KEY_1 = P2^7;

extern void InitLcd1602();
extern void LcdShowStr(unsigned char x, unsigned char y, unsigned char *str);

void Delay50ms();
void PCA_Init (bit module);
void IntToString(unsigned char *str, unsigned int dat);

void main (void)
{
PCA_Init(0);
InitLcd1602();
P2 = 0xF7;

while(1)
{
if(!KEY_1)
{
Delay50ms();
if(!KEY_1)
{
while(!KEY_1);
CCAPM0 = 0x11;
CR = 1;
}
}

if(Capture_over)
{
Capture_over = 0;
//                           g_Frequency = (long)1000000 / g_Period;
g_Frequency = (long)11059200 / (g_Period * 12);

IntToString(str1, g_Period);
IntToString(str2, g_Frequency);
LcdShowStr(1, 0, "length:");
LcdShowStr(8, 0, str1);
LcdShowStr(1, 1, "freque:");
LcdShowStr(8, 1, str2);

}
}
}

void PCA_Init (bit module)
{
//CIDL    -       -       -       CPS2    CPS1    CPS0    ECF
CMOD = 0x80;

//CF      CR      -       -       -       -       CCF1    CCF0
CCON = 0x00;

if (module == 0)
{
CCAPM0 = 0x10;
CCAP0L = 0x00;
CCAP0H = 0x00;
}
else
{
CCAPM1 = 0x11;
CCAP1L = 0x00;
CCAP1H = 0x00;
}

CL = 0x00;
CH = 0x00;

EA = 1;

//CR = 1;
}

void IntToString(unsigned char *str, unsigned int dat)
{
unsigned char buf[12];
unsigned char i = 0;
do{
buf[i++] = dat % 10;
dat /= 10;
}while(dat > 0);

while(i-- > 0)
{
*str++ = buf[i] + '0';//数组转换成ASCII反向拷贝到字符串指针
}
*str = '\0';
}

void PCA_Int(void) interrupt 7
{
if (CCF0)
{
CCF0 = 0;
if(Last_Capture_Data == 0)
{
Last_Capture_Data = CCAP0H;

Last_Capture_Data = (Last_Capture_Data << 8) + CCAP0L;
}
else
{
New_Capture_Data = CCAP0H;

New_Capture_Data = (New_Capture_Data << 8) + CCAP0L;
g_Period = New_Capture_Data - Last_Capture_Data;
CR = 0;
CCAPM0 = 0x10;

Last_Capture_Data=0;
CCAP0L = 0x00;
CCAP0H = 0x00;
CL = 0x00;
CH = 0x00;

Capture_over = 1;
}
}

}

void Delay50ms()        //@11.0592MHz
{
unsigned char i, j, k;

i = 3;
j = 26;
k = 223;
do
{
do
{
while (--k);
} while (--j);
} while (--i);
}

配置流程：

CMOD 设置禁止溢出中断

设置CCAPMx设置开启捕获中断，以及上升沿捕获还是下降沿捕获

清零CCnPL、CCnPH以及CH、CL



其实最重要的还得看手册，介绍的真心很详细！！！

一个非常详细的电路图，分分享一下：



很明显，图的意思就是设置好上升沿捕获或者下降沿捕获后，由于CL、CH

一直在走，一旦满足条件就把CL./CH的值分别装入CCAPL以及CCAPH中，如果此时使能PCA中断的话，会触发中断进入中断。