#include <reg51.h>
#include <absacc.h>
#include <stdio.h>
#include <intrins.h>
#include <math.h>
#include <string.h>

//NJU39610端口定义
 
#define DA_PORT P1 
sbit DA_WR=P3^4;        //NJU39610数据写入端；
sbit DA_A0=P3^7;        //NJU39610通道选择端；

//对外接口引脚定义
sbit ST_CLK =P3^2;      //外部脉冲信号输入；
sbit ST_STOP=P3^3;      //控制步进电机开关；
sbit ST_DIR =P2^7;      //控制步进电机转动方向；

//全局变量定义 
unsigned char data  xf_step;                                           //细分步数（二相电机单二拍走一循环为64步）
unsigned char xdata xf32_sin[64]={0,6,12,18,24,31,37,43,               //32细分后走一个循环的细分数据；
                                  48,54,60,65,71,76,81,85,
                                  90,94,98,102,106,109,112,115,
                                  118,120,122,124,125,126,127,127,
                                  128,127,127,126,125,124,122,120,
                                  118,115,112,109,106,102,98,94,
                                  90,85,81,76,71,65,60,54,
                                  48,43,37,31,24,18,12,6
                                 };
unsigned char xdata xf32_cos[64]={128,127,127,126,125,124,122,120,
                                  118,115,112,109,106,102,98,94,
                                  90,85,81,76,71,65,60,54,
                                  48,43,37,31,24,18,12,6,
                                  0,6,12,18,24,31,37,43,
                                  48,54,60,65,71,76,81,85,
                                  90,94,98,102,106,109,112,115,
                                  118,120,122,124,125,126,127,127,
                                 };

StopMt()
{
       DA_A0=0;                         //选DA通道0；
       DA_PORT=0;
       DA_WR=0;                         //DA数据写入；
       _nop_();
       DA_WR=1;
       DA_A0=1;                         //选DA通道1；
       DA_PORT=0;
       DA_WR=0;                         //DA数据写入；
       _nop_();
       DA_WR=1;
}

void t0(void)interrupt 1 using 0
{
   TH0=(65536-500)/256;
   TL0=(65536-500)/256;             
   if(ST_DIR)                           //如果ST_DIR为1，则电机正转，D7位为低电平
     {
       DA_A0=0;                         //选DA通道0；
       DA_PORT=xf32_sin[xf_step]|0x80;
       DA_WR=0;                         //DA数据写入；
       _nop_();
       DA_WR=1;
       DA_A0=1;                         //选DA通道1；
       DA_PORT=xf32_cos[xf_step]|0x80;
       DA_WR=0;                         //DA数据写入；
       _nop_();
       DA_WR=1;
     }
   else                                 //如果ST_DIR为0，则电机反转，D7位为高电平
     {
       DA_A0=0;                         //选DA通道0；
       DA_PORT=xf32_sin[xf_step];
       DA_WR=0;                         //DA数据写入；
       _nop_();
       DA_WR=1;
       DA_A0=1;                         //选DA通道1；
       DA_PORT=xf32_cos[xf_step];
       DA_WR=0;                         //DA数据写入；
       _nop_(); 
       DA_WR=1;
     }
   xf_step++;                           //0.5ms进次中断，电机走一步，每走64步重新循环
   if(xf_step>=64) {xf_step=0;}
}
void main(void)
{         
   TMOD=0x01;
   TH0=(65536-500)/256;
   TL0=(65536-500)/256;
   TR0=1;
   ET0=1;
   EA=1;         //开放系统中断
   StopMt();
   while(1);
}