196 lines
3.6 KiB
C
196 lines
3.6 KiB
C
/*
|
||
程序说明: IIC总线驱动程序
|
||
软件环境: Keil uVision 4.10
|
||
硬件环境: CT107单片机综合实训平台 8051，12MHz
|
||
日 期: 2011-8-9
|
||
*/
|
||
|
||
#include "iic.h"
|
||
|
||
|
||
#include "intrins.h"
|
||
|
||
#define DELAY_TIME 5
|
||
|
||
#define Photo_Res_Channel 0x41
|
||
#define Adj_Res_Channel 0x43
|
||
|
||
|
||
//总线引脚定义
|
||
sbit SDA = P2^1; /* 数据线 */
|
||
sbit SCL = P2^0; /* 时钟线 */
|
||
|
||
void IIC_Delay(unsigned char i)
|
||
{
|
||
do {
|
||
_nop_();
|
||
}
|
||
while(i--);
|
||
}
|
||
|
||
//总线启动条件
|
||
void IIC_Start(void)
|
||
{
|
||
SDA = 1;
|
||
SCL = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
SDA = 0;
|
||
IIC_Delay(DELAY_TIME);
|
||
SCL = 0;
|
||
}
|
||
|
||
//总线停止条件
|
||
void IIC_Stop(void)
|
||
{
|
||
SDA = 0;
|
||
SCL = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
SDA = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
}
|
||
|
||
//发送应答
|
||
void IIC_SendAck(bit ackbit)
|
||
{
|
||
SCL = 0;
|
||
SDA = ackbit; // 0：应答，1：非应答
|
||
IIC_Delay(DELAY_TIME);
|
||
SCL = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
SCL = 0;
|
||
SDA = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
}
|
||
|
||
//等待应答
|
||
bit IIC_WaitAck(void)
|
||
{
|
||
bit ackbit;
|
||
|
||
SCL = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
ackbit = SDA;
|
||
SCL = 0;
|
||
IIC_Delay(DELAY_TIME);
|
||
return ackbit;
|
||
}
|
||
|
||
//通过I2C总线发送数据
|
||
void IIC_SendByte(unsigned char byt)
|
||
{
|
||
unsigned char i;
|
||
|
||
for(i=0; i<8; i++)
|
||
{
|
||
SCL = 0;
|
||
IIC_Delay(DELAY_TIME);
|
||
if(byt & 0x80) SDA = 1;
|
||
else SDA = 0;
|
||
IIC_Delay(DELAY_TIME);
|
||
SCL = 1;
|
||
byt <<= 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
}
|
||
SCL = 0;
|
||
}
|
||
|
||
//从I2C总线上接收数据
|
||
unsigned char IIC_RecByte(void)
|
||
{
|
||
unsigned char i, da;
|
||
for(i=0; i<8; i++)
|
||
{
|
||
SCL = 1;
|
||
IIC_Delay(DELAY_TIME);
|
||
da <<= 1;
|
||
if(SDA) da |= 1;
|
||
SCL = 0;
|
||
IIC_Delay(DELAY_TIME);
|
||
}
|
||
return da;
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
unsigned char Ad_Read(unsigned char addr)
|
||
{
|
||
unsigned char temp;
|
||
IIC_Start();
|
||
IIC_SendByte(0x90);
|
||
IIC_WaitAck();
|
||
IIC_SendByte(addr);
|
||
IIC_WaitAck();
|
||
IIC_Start();
|
||
IIC_SendByte(0x91);
|
||
IIC_WaitAck();
|
||
temp = IIC_RecByte();
|
||
IIC_SendAck(1);
|
||
IIC_Stop();
|
||
return temp;
|
||
}
|
||
|
||
void Da_Write(unsigned char dat)
|
||
{
|
||
IIC_Start();
|
||
IIC_SendByte(0x90);
|
||
IIC_WaitAck();
|
||
IIC_SendByte(0x41);
|
||
IIC_WaitAck();
|
||
IIC_SendByte(dat);
|
||
IIC_WaitAck();
|
||
IIC_Stop();
|
||
}
|
||
|
||
|
||
|
||
//函数名：写EEPROM函数
|
||
//入口参数：需要写入的字符串，写入的地址(务必为8的倍数)，写入数量
|
||
//返回值：无
|
||
//函数功能：向EERPOM的某个地址写入字符串中特定数量的字符。
|
||
void EEPROM_Write(unsigned char* EEPROM_String, unsigned char addr, unsigned char num)
|
||
{
|
||
IIC_Start();//发送开启信号
|
||
IIC_SendByte(0xA0);//选择EEPROM芯片，确定写的模式
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
|
||
IIC_SendByte(addr);//写入要存储的数据地址
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
|
||
while(num--)
|
||
{
|
||
IIC_SendByte(*EEPROM_String++);//将要写入的信息写入
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
IIC_Delay(200);
|
||
}
|
||
IIC_Stop();//停止发送
|
||
}
|
||
|
||
|
||
//函数名：读EEPROM函数
|
||
//入口参数：读到的数据需要存储的字符串，读取的地址(务必为8的倍数)，读取的数量
|
||
//返回值：无
|
||
//函数功能：读取EERPOM的某个地址中的数据，并存放在字符串数组中。
|
||
void EEPROM_Read(unsigned char* EEPROM_String, unsigned char addr, unsigned char num)
|
||
{
|
||
IIC_Start();//发送开启信号
|
||
IIC_SendByte(0xA0);//选择EEPROM芯片，确定写的模式
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
|
||
IIC_SendByte(addr);//写入要读取的数据地址
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
|
||
IIC_Start();//发送开启信号
|
||
IIC_SendByte(0xA1);//选择EEPROM芯片，确定读的模式
|
||
IIC_WaitAck();//等待EEPROM反馈
|
||
|
||
while(num--)
|
||
{
|
||
*EEPROM_String++ = IIC_RecByte();//将要写入的信息写入
|
||
if(num) IIC_SendAck(0);//发送应答
|
||
else IIC_SendAck(1);//不应答
|
||
}
|
||
|
||
IIC_Stop();//停止发送
|
||
} |