STC12c2052 PCA 捕捉出现的问题。

只看该作者 · 2012-9-19 21:47

我的问题是：采集数据比如50个数据，中间会有几个频率值不对的情况。
if( cap_tar==0)
      {
///CH=0；CL=0；
      C16BIT.CH[1] = CCAP0L;
      C16BIT.CH[0] = CCAP0H;
      }
如果将PCA的计数器清零，采集的数据的就可以正常的。但是因为还要用到PCA 软件定时功能，所以不能将计数器清零。请帮我找一下问题是在哪里？应该怎么更正。

#include "stc2052.h"
#define uchar unsigned char
#define uint unsigned int
/*Declare SFR associated with the PCA */
sbit EPCAI    = IE^6;
sbit PCA_LED = P1^6;                //PCA test LED
uchar idata SERSEND[16];
uint L_cnt = 0;
uchar Send_count;
bit Ready;
uint cap_tar;
unsigned long count;
unsigned long  getfr;
unsigned int Fre_range=800;
uint value,T1K_LOW,T1K_HIGH;
union                // 4-byte?LONG ????
  {
unsigned long  Result;
uint C16BIT[2];
uchar CH[4];
  }C32BIT;
union                // 2-byte?uint ????
  {
uint Result;
uchar CH[2];
  }C16BIT;
void  Set_Parm();
void  RS232(void);
void PCA_isr() interrupt 6 using 1
  {
static bit FLAG;
if (CCF0)                         // PCA模块0捕捉中断入口
{
   CCF0 = 0;                         // Clear interrupt flag
   if( cap_tar==0)
      {
      C16BIT.CH[1] = CCAP0L;
   C16BIT.CH[0] = CCAP0H;
      }
      cap_tar++;
   C32BIT.CH[2] =CCAP0H;
   C32BIT.CH[3] = CCAP0L;;
   C32BIT.CH[1] = L_cnt;
   Ready = 1;                            // Enable
}
if(CF)                      // PCA溢出中断入口
{
   L_cnt ++;                   //PCA计数器溢出的值
   CF = 0;                   // Clear interrupt flag
   }
  if (CCF1)                   // PCA模块1中断入口
  {
   CCF1 = 0;                // Clear interrupt flag
   T1K_LOW=12000-T1K_HIGH;    // 占空比的值计算
   if (FLAG)
   {
      FLAG = 0;
      PCA_LED = 1;             //
      value = value+T1K_HIGH;
   CCAP1L = value;          // First
      CCAP1H = value >>8;    // Second
   }
   else
   {
      FLAG = 1;
      PCA_LED = 0;          // PWM???
      value=value+T1K_LOW;
   CCAP1L = value ;       // First
      CCAP1H = value >>8;    // Second
   }
   }

  }

void main()
  {
T1K_LOW  = 1480;                // ????,???????(?=12000)
T1K_HIGH = 10520;                // ????,???????(?=12000)
CCAP1L = T1K_LOW;
CCAP1H = T1K_HIGH;
Set_Parm();
for(;;)
   {
   if (Ready)
      {
   count = C32BIT.Result - C16BIT.Result;
if(count>12000000) ////定时器1S到采集频率
      {
         L_cnt=0;
         getfr=cap_tar;
         cap_tar=0;
         }
         if (Send_count == 0)
         {
      SERSEND[1] = getfr;
         SERSEND[2] = getfr>>8;

         }
Ready = 0;
}
}
  }

void Set_Parm()                            // 程序初始化
{
TMOD    = 0x21;                      // T1???????, T0?8????????
SCON    = 0x5c;                      // ??????:MODE3
PCON    = 0x80;                      // SMOD = 1
TH1    = 0xf3;                      // ????/9600BPS
TR1    = 1;                         // T1??(1=??; 0=??), ????????
AUXR    = 0x00;
SCON    = 0x40;
REN    = 1;                         // ???1????
CCON    = 0x80;                      // Initial PCA control register
                                          // PCA timer stop running
                                          // Clear CF flag
                                          // Clear all module interrupt flag
CL    = 0;                         // Reset PCA base timer
CH    = 0;
CMOD    = 0x03;                      // Set PCA timer clock source as Fosc/2
                                          // Disable PCA timer overflow interrupt
CCAPM0 = 0x11;                      // PCA module-0 capture by a negative tigger on CEX0(P3.7) and enable PCA interrupt
CCAPM1 = 0x49;                      // PCA module-0 capture by a negative tigger on CEX0(P3.7) and enable PCA interrupt
CR    = 1;                         // PCA timer start run
IPH    = 0x80;
PPCA_LVD  = 1;                         //PCA中断优先级高
EPCAI = 1;
ES    = 1;
EA    = 1;
}

void RS232(void) interrupt 4 using 3    /////串口接收发送中断
  {
uchar RS232CMD;
uchar i;
if (TI)
{
  TI = 0;
   Send_count --;
   if (Send_count > 0)
   {
   for (i=0; i<Send_count; i++)
   SERSEND = SERSEND[i+1];
   SBUF = SERSEND[0];
   }
  return;
}
if (!RI) return;
RI = 0;
RS232CMD = SBUF;
if (RS232CMD == 0x05)
{
   if (Send_count == 0)
   {
      SERSEND[0] = 0xFF;
      Send_count = 3;
      SBUF = SERSEND[0];
   }
}
}