大家帮我看一看模拟IIC的程序，为什么出不来数

只看该作者 · 2013-8-26 18:06

本人想利用TQ2440和AD5933做一个阻抗信号的采集，不知道为什么，最后出来的数清一色的是30005fb8
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，奇怪，发出代码，希望大家帮忙指正错误

#include "def.h"
#include "option.h"
#include "2440addr.h"
#include "2440lib.h"
#include "2440slib.h"

#define Set_SDA()    rGPEDAT |= (1<<15)
#define Clr_SDA()    rGPEDAT &= ~(1<<15)

#define Set_SCL()    rGPEDAT |= (1<<14)
#define Clr_SCL()    rGPEDAT &= ~(1<<14)


void init() //初始化
{

Set_SCL();
Delay(1);
Set_SDA();
Delay(1);

}

void start() //启动信号
{

Set_SDA();
Set_SCL();
Delay(1);

Clr_SDA();
Delay(1);
Clr_SCL();
Delay(1);

}

int ack()    //应答信号
{

unsigned short temp;

rGPECON = 0x10000000;
Delay(1);

Set_SCL();
Delay(1);

temp = rGPEDAT & (1<<15);
Delay(1);

Clr_SCL();
Delay(1);

rGPECON = 0x50000000;
Delay(1);

if(temp)
   return 1;
else
   return 0;

}

void stop()    //停止信号
{

Set_SCL();
Clr_SDA();
Delay(1);

Set_SCL();
Delay(1);
Set_SDA();
Delay(1);

}

void writebyte(unsigned short data)  //写一个字节
{

unsigned short i;

for(i=0;i<8;i++)
{

   if(data & (1<<(7-i)))
      Set_SDA();
   else
      Clr_SDA();
   Delay(1);

   Set_SCL();
   Delay(1);
   Clr_SCL();

}

Delay(1);
}

int readbyte() //读一个字节
{

unsigned short i;
U8 temp = 0;

rGPECON = 0x10000000;
Delay(1);

for(i=0;i<8;i++)
{

   Set_SDA();

   if(rGPEDAT & (1<<15))
      temp |= (1<<(7-i));
   Delay(1);

   Set_SCL();
   Delay(1);

   Clr_SCL();
   Delay(1);

}

rGPECON = 0x50000000;

Set_SDA();
Delay(1);

return temp;

}

void _wr(unsigned short slv,unsigned short reg,unsigned short data)
{

start();

writebyte(slv);
if(ack())
{

   stop();
   return;

}

start();
writebyte(reg);
if(ack())
{

   stop();
   return;

}

writebyte(data);
if(ack())
{

   stop();
   return;

}

stop();

}

void _rd(U32 reg,unsigned short data)
{
unsigned short temp;

start();

writebyte(0x1a);
if(ack())
{

   stop();
   return;

}

writebyte(reg);
if(ack())
{

   stop();
   return;

}

writebyte(0x1b);
if(ack())
{

   stop();
   return;

}

Delay(1);

readbyte();

data = readbyte();

stop();

}

void iic()
{

   unsigned short temp;

   rGPEUP  = 0xc000;
   rGPECON = 0x50000000;

   init();

   _wr(0x1a,0x82,0x19);  //start frequency
   Delay(5);
   _wr(0x1a,0x83,0x99);  //50kHz
   Delay(5);
   _wr(0x1a,0x84,0x99);
   Delay(5);

   _wr(0x1a,0x81,0x08);  //选着外部时钟
   Delay(5);
   _wr(0x1a,0x80,0x11);
   Delay(5);

   _wr(0x1a,0x8f,0x02);
   Delay(5);

   while(1)
   {

      _rd(0x1b,temp);

      Uart_Printf("%x\n",temp);

      Delay(200);

   }
}