本帖最后由 hotpower 于 2010-9-7 01:13 编辑
菜农此I2C模板应用8年未尝败绩，大家可以和NXP例程对比，
俺就不公开和NXP“PK”了~~~
//i2c.h
#include "main.h"
#ifndef __LPC11xxI2c_H__
#define __LPC11xxI2c_H__
#ifdef __cplusplus
extern "C" {
#endif
class I2cObj;
class I2cObj {//系统串口类
public:
I2cObj(unsigned char I2CAddress = 0xa1);
private:
inline void I2cInit(void);
public:
inline void Start(void);
inline void REStart(void);
inline void Stop(void);
inline void Exit(void);
inline void Exec(void);
void SetAddress(unsigned char I2CAddress);
void WriteWait(void);
unsigned char ReadByte(unsigned char, unsigned char &);
unsigned char WriteByte(unsigned char, unsigned char);
public:
volatile bool Busy;
volatile unsigned int State;
volatile unsigned int Count;
volatile unsigned int MainCount, SubCount;
volatile unsigned char SubAddr;
volatile unsigned char MainComm, SubComm;
volatile unsigned char TxBuffer[16], RxBuffer[16];//接收数据缓冲区
};
extern "C" void __irq I2C_IRQHandler(void);
#ifdef __cplusplus
}
#endif
#endif//__LPC11xxI2c_H__
//i2c.cpp
#include "i2c.h"
extern "C" void __irq I2C_IRQHandler(void)
{
I2c.Exec();
}
I2cObj::I2cObj (unsigned char I2CAddress)
{
SubAddr = I2CAddress;
I2cInit();
}
void I2cObj::I2cInit(void)
{
SYSCON.PRESETCTRL.Bits.I2C0_RST_N = 1;//复位I2C,否则死机
SYSCON.SYSAHBCLKCTRL.Bits.I2CCLK = 1;
//位域写法
IOCON.PIO0_4.Bits.FUNC = IOCON_SCL;//选择PIO0.4为I2C_SCL
IOCON.PIO0_4.Bits.I2CMODE = IOCON_SCL_I2CMODE;//选择PIO0.4为I2C_SCL
IOCON.PIO0_5.Bits.FUNC = IOCON_SDA;//选择PIO0.5为I2C_SCL
IOCON.PIO0_5.Bits.I2CMODE = IOCON_SDA_I2CMODE;//选择PIO0.5为I2C_SDA
//寄存器写法
/*
IOCON.PIO0_4.Regs = (IOCON_SCL << IOCON_FUNC)
| (IOCON_SCL_I2CMODE << IOCON_I2CMODE);
IOCON.PIO0_5.Regs = (IOCON_SDA << IOCON_FUNC)
| (IOCON_SDA_I2CMODE << IOCON_I2CMODE);
*/
I2C0.SCLL.Regs = 0x00000180;
I2C0.SCLH.Regs = 0x00000180;
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI);
I2C0.CONSET.Bits.I2EN = 1;
for (int i = 0; i < sizeof(TxBuffer); i ++) {
TxBuffer = 0;
RxBuffer = 0;
}
Exit();//通讯失败
nVIC.ISER.Bits.I2C_IRQn = 1;
}
void I2cObj::SetAddress(unsigned char I2CAddress)
{
SubAddr = I2CAddress;
}
void I2cObj::Start(void)
{
Busy = true;
State = I2C_START;//主机准备发送启始位
Count = 0;//发送数据个数
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STA);//设置使能起始标志
}
void I2cObj::REStart(void)
{
Busy = true;
State = I2C_REP_START;//主机准备发送启始位
Count = 0;//发送数据个数
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除标志
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STA);//设置使能起始标志
}
void I2cObj::Stop(void)
{
Busy = false;
State = I2C_BUS_OK;//通讯成功
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STO);
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);
}
void I2cObj::Exit(void)
{
Busy = false;
State = I2C_BUS_ERROR;//通讯失败
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STO);
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);
}
void I2cObj::WriteWait(void)
{
for(int i = 0; i < 18888; i ++)
{
__nop();//延时等待写入完成
}
}
void I2cObj::Exec(void)
{
switch(I2C0.STAT.Regs & 0xf8) {
case I2C_START://主机收到自己发送的开始信号
if (State == I2C_START) {//本次中断应该接收TW_START信号
I2C0.DAT.Regs = SubAddr & 0xfe;//发送子机地址(写)
State = I2C_MT_SLA_ACK;//Status下次I2C_MT_SLA_ACK
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中断标志
}
else Exit();//通讯失败
break;
case I2C_REP_START://主机收到自己发送的重新开始信号
if (State == I2C_REP_START) {//本次中断应该接收TW_RESTART信号
I2C0.DAT.Regs = SubAddr | 0x01;//发送子机地址(读)
State = I2C_MR_SLA_ACK;//Status下次I2C_MR_SLA_ACK
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中断标志
}
else Exit();//通讯失败
break;
case I2C_MT_SLA_ACK://主发机接收到从机的地址应答信号后发送命令
if (State == I2C_MT_SLA_ACK) {//本次中断应该接收TW_MT_SLA_ACK信号
State = I2C_MT_DATA_ACK;//Status下次应该收TW_MT_DATA_ACK
I2C0.DAT.Regs = SubComm;//发送子机命令
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中断标志
}
else Exit();//通讯失败
break;
case I2C_MR_SLA_ACK://主收机接收到从机的地址应答信号
if ((State == I2C_MR_SLA_ACK) && SubCount) {//本次中断应该接收TW_MR_SLA_ACK信号
State = I2C_MR_DATA_ACK;//Status下次应该收TW_MR_DATA_ACK
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI);//清除中断标志,主机转入接收状态
I2C0.CONSET.Bits.AA = 1;
}
else Exit();//通讯失败
break;
case I2C_MT_DATA_ACK://主收机接收到从机的数据应答信号
if ((State == I2C_MT_DATA_ACK) && (Count < MainCount)) {//本次中断应该接收TW_MT_DATA_ACK信号
I2C0.DAT.Regs = TxBuffer[Count ++];//发送子机数据
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中断标志
}
else {
if ((State == I2C_MT_DATA_ACK) && (Count == MainCount) && (SubAddr & 1)) {//本次中断应该接收TW_MT_DATA_ACK信号
REStart();//
}
else Stop();//通讯成功
}
break;
case I2C_MR_DATA_ACK:
if ((State == I2C_MR_DATA_ACK) && (Count < SubCount)) {
RxBuffer[Count ++] = I2C0.DAT.Regs;//接收子机数据
if (Count < SubCount) {
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI);//主机转入接收状态
I2C0.CONSET.Bits.AA = 1;
}
else {
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中断标志,主机转入接收状态
State = I2C_MR_DATA_NACK;//下次进入I2C_MR_DATA_NACK，接收数据准备完成
}
}
else Exit();//通讯失败
break;
case I2C_MR_DATA_NACK://数据接收结束
if ((State == I2C_MR_DATA_NACK) && (Count == SubCount)) {
Stop();//通讯成功
}
else Exit();//通讯失败
break;
// case I2C_MT_DATA_NACK:
// Exit();//通讯失败
// break;
default:
Exit();//通讯失败
}
}
unsigned char I2cObj::ReadByte(unsigned char Address, unsigned char & Data)
{
SubAddr |= 0x01;
MainCount = 0;//发送0个数据(只读)
//本程序为通用I2C,故发送器件后一般为命令，对EEPROM来说，命令实际是EEPROM地址
SubComm = Address;//读出地址
SubCount = 1;//接收1个数据
Start();
while (Busy);
if (State == I2C_BUS_OK) {//通讯成功
Data = RxBuffer[0];//取出一个字节
}
return State;//(读出数据在RxBuffer[0]~RxBuffer[15])
}
unsigned char I2cObj::WriteByte(unsigned char Address, unsigned char Data)
{
SubAddr &= 0xfe;
MainCount = 1;//发送1个数据
//本程序为通用I2C,故发送器件后一般为命令，对EEPROM来说，命令实际是EEPROM地址
SubComm = Address;//写入地址
TxBuffer[0] = Data;//写入数据
SubCount = 0;//接收0个数据
Start();
while (Busy);
if (State == I2C_BUS_OK) {//通讯成功
PortLed1.DATA.Bits.PinLed1 = 0;//LED1亮
}
return State;
}
//读LM75
I2c.SetAddress(0x90);//设置LM75器件地址
I2c.WriteByte(1, Data);//写配置命令1
I2c.ReadByte(0, Data);//读温度命令0
Uart.Send(Data);
//读写AT24C16
I2c.SetAddress(0xa0);//设置AT24C16器件地址
for (int i = 1; i < 16; i ++)//延时
{
I2c.WriteByte(i, i);//写入EEPROM一个字节
I2c.WriteWait();//延时等待写入完成
I2c.ReadByte(i, Data);//读出EEPROM一个字节
Uart.Send(Data);
}
HotPower@163.com 2010.9.6 23:58 于雁塔菜地
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