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标题: 8254三路计数的程序 [打印本页]

作者: 左耳 时间: 2016-5-30 17:25
标题: 8254三路计数的程序
C语言功底不好，希望大家帮忙优化

另外，把整体的初始化程序分成3个写，出现第二个或第三个计数器高低位读反的情况，这是为什么？

用于小车车速计数使用的

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
L8254.H

/*
说明：
主函数中定义
volatile long int num_8254_0,num_8254_1,num_8254_2;
volatile long int speed_count_0,speed_count_1,speed_count_2;
然后包含8254.h和8254.c

首先初始化
void counter_8254_init(void);

就可以直接引用
void counter_8254_read(void);

num_8254_N输出的对应计数器的计数值（从初始化到中断这段时间内）

speed_result(void);

输出的speed_count_N就是编码器转数（如果不需要，则直接使用counter_8254_read）

接线：
12接地 24VCC
引脚1到8 即D7-0接PORTB7-0
23WR接PORTA_PA0
22RD接PORTA_PA1
21CS接PORTA_PA2
20A1接PORTA_PA3
19A0接PORTA_PA4

11GT0接 PORTA_PA5
14GT1接 PORTA_PA6
16GT2接 PORTA_PA7

9CLK0输入0的脉冲
15CLK1输入1的脉冲
18CLK2输入2的脉冲
*/

#ifndef _8254_H
#define _8254_H

#define uchar unsigned char
#define uint unsigned int

#define counter_data_port_dire DDRB //所用的数据口的方向寄存器
#define counter_data_port PORTB    //所用的数据口
#define wr PORTA_PA0
#define rd PORTA_PA1
#define CS PORTA_PA2
#define A1 PORTA_PA3
#define A0 PORTA_PA4
#define GT0 PORTA_PA5
#define GT1 PORTA_PA6
#define GT2 PORTA_PA7

#define Count_Time_0 1 //计数的周期，Nms
#define Count_Time_1 1
#define Count_Time_2 1
#define N_Coder_0 500 //编码器线数
#define N_Coder_1 500
#define N_Coder_2 500

void counter_8254_init(void);

void counter_8254_read(void);

void speed_result(void);

#endif

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
L8254.C

#include <hidef.h>
#include "derivative.h"
#include "8254.h"

/****************************************
函数?void counter_8254_read_N(void)
功能：读8254的N计数器当前计数值
说明：
*******************************************/
void counter_8254_read(void)
{
  uint num_L= 0,num_H = 0;
  extern long int num_8254_0;
  extern long int num_8254_1;
  extern long int num_8254_2;
//////////////////////////
  counter_data_port_dire = 0xFF;
  counter_data_port = 0x00;
  A1 = 1;
  A0 = 1;
  rd = 1;
  wr = 0;
  CS = 0;
  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 0;
  A1 = 0;
  counter_data_port_dire = 0x00;
  num_L = counter_data_port;
  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 0;
  A1 = 0;
  num_H = counter_data_port;

  num_L = 0xFF - num_L; //分两次读出，由于82C54是减法计数器，所以要被OxFF减
  num_H = 0xFF - num_H;
  num_8254_0 = (long int)num_H*256+num_L; //将两个八位整合成一个十六位数据

  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 1;
  A1 = 0;
  counter_data_port_dire = 0x00;
  num_L = counter_data_port;
  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 1;
  A1 = 0;
  num_H = counter_data_port;

  num_L = 0xFF - num_L; //分两次读出，由于82C54是减法计数器，所以要被OxFF减
  num_H = 0xFF - num_H;
  num_8254_1 = (long int)num_H*256+num_L; //将两个八位整合成一个十六位数据

  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 0;
  A1 = 1;
  counter_data_port_dire = 0x00;
  num_L = counter_data_port;
  CS = 1;
  wr = 1;

  CS = 0;
  wr = 1;
  rd = 0;
  A0 = 0;
  A1 = 1;
  num_H = counter_data_port;

  num_L = 0xFF - num_L; //分两次读出，由于82C54是减法计数器，所以要被OxFF减
  num_H = 0xFF - num_H;
  num_8254_2 = (long int)num_H*256+num_L; //将两个八位整合成一个十六位数据
}

/****************************************
函数?void speed_result(void)
功能：通过计数器的值来计算相应的转速
说明：
*******************************************/
void speed_result(void)
{
  extern long int speed_count_0;
  extern long int num_8254_0;
  extern long int speed_count_1;
  extern long int num_8254_1;
  extern long int speed_count_2;
  extern long int num_8254_2;

  counter_8254_read();

  speed_count_0 = num_8254_0*(1000/Count_Time_0)/N_Coder_0;
  speed_count_1 = num_8254_1*(1000/Count_Time_1)/N_Coder_1;
  speed_count_2 = num_8254_2*(1000/Count_Time_2)/N_Coder_2;
}

/****************************************
函数：void counter_8254_init(void)
功能：8254的计数器的初始化
说明：对8254进行控制字写入并设置计数初值
*******************************************/

void counter_8254_init(void)
{
  //计数初始化
  CS = 0;
  GT0 = 1; //#0
  GT1 = 1;
  GT2 = 1;

  CS = 1;
  wr = 1;

  counter_data_port_dire = 0xFF;

  counter_data_port = 0x30;       //选择0#。先低8再高8位，方式0，二进制16位计数方式
  A1 = 1;
  A0 = 1; //写控制字
  wr = 0; //写操作
  CS = 0;
  rd = 1;

  CS = 1;
  wr = 1;

  counter_data_port = 0x70;       //选择1#。先低8再高8位，方式0，二进制16位计数方式
  A1 = 1;
  A0 = 1; //写控制字
  wr = 0; //写操作
  CS = 0;
  rd = 1;

  CS = 1;
  wr = 1;


  counter_data_port = 0xB0;       //选择2#。先低8再高8位，方式0，二进制16位计数方式
  A1 = 1;
  A0 = 1; //写控制字
  wr = 0; //写操作
  CS = 0;
  rd = 1;

  CS = 1;
  wr = 1;

//////////////////////////
  counter_data_port = 0xFF; //低
  A0 = 0;
  A1 = 0; //#0
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

  counter_data_port = 0xFF; //高
  A0 = 0;
  A1 = 0; //#0
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

//////////////////////////
  counter_data_port = 0xFF; //低
  A0 = 1;
  A1 = 0; //#1
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

  counter_data_port = 0xFF; //高
  A0 = 1;
  A1 = 0; //#1
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

//////////////////////////
  counter_data_port = 0xFF; //低
  A0 = 0;
  A1 = 1; //#2
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

  counter_data_port = 0xFF; //高
  A0 = 0;
  A1 = 1; //#2
  rd = 1;
  wr = 0; //写
  CS = 0;

  wr = 1;
  CS = 1;

  counter_data_port = 0x00;
}

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