请问硬件I2C如何设计的？我总是调不通啊

只看该作者 · 2010-10-18 17:27

只看该作者 · 2010-10-18 17:29

请看https://bbs.21ic.com/frame.php?fr ... .com/iclist-49.html
里面有详细的介绍。

只看该作者 · 2010-10-18 17:29

https://bbs.21ic.com/frame.php?fr ... .com/iclist-49.html

只看该作者 · 2010-10-18 17:30

jgphu发表于 2010-10-18 14:57 | 只看该作者回复引用编辑评分返回版面 TOP  得分：0
6楼：还有下面的
#include "iic.h"

void IIC_Init(void)
{
      UCHAR temp;

      CLK_PCKENR1 |= 0x01;

      I2C_FREQR |= 0x10;                //输入外设时钟频率为1MHz
      I2C_CR1 = 0x00;                //禁止I2C外设
      I2C_CCRH  &= ~0xcf;
      I2C_CCRL  &= ~0xff;
  I2C_TRISER = 0x11;
      I2C_CCRL = 0x10;
      I2C_CCRH = 0x00;
      I2C_CR1 |= 0x01;                //开启I2C外设
      I2C_CR2 |= 0x04;                //当前接收字节返回应答
      I2C_CR2 &= 0x08;
      I2C_OARL = 0x86;                //自身地址
      I2C_OARH = 0x40;
}

void Read_8816(UCHAR *pBuffer, UCHAR index, UCHAR NumByteToRead)
{
      UCHAR temp;

      while(I2C_SR3 & 0x02);          //等待总线空闲
      I2C_CR2 |= 0x01;                               //产生起始位
      while(!(I2C_SR1 & 0x01));       //等待START发送完
      I2C_DR = 0x8a;                   //发送8816器件地址
      while(!(I2C_SR1 & 0x02));       //等特7位器件地址发送完
      temp = I2C_SR1;
      temp = I2C_SR3;
      I2C_DR = (UCHAR)(index);
      while(!(I2C_SR1 & 0x84));

      I2C_CR2 |= 0x01;                                     //产生重复起始位
      while(!(I2C_SR1 & 0x01));       //等待START发送完
      I2C_DR = 0x8b;                   //读
      while(!(I2C_SR1 & 0x02));       //等特7位器件地址发送完
      temp = I2C_SR1;
      temp = I2C_SR3;
      while(NumByteToRead)                   //要读几个字节
      {
            if(NumByteToRead == 1)
            {
                     I2C_CR2 &= ~0x04;             //不返回应答
                     I2C_CR2 |= 0x02;             //产生停止位
            }
            if(I2C_SR1 & 0x40)
            {
                     temp = I2C_SR1;
                     *pBuffer = I2C_DR;
                     pBuffer++;
                     NumByteToRead--;
            }
      }
      I2C_CR2 |= 0x04;
      I2C_CR2 &= ~0x08;                //为下一次接收使能应答
}