CortexM0菜鳥之I2C主機中斷(第10天作業)

hotpower

菜農此I2C模板應用8年未嘗敗績，大家可以和NXP例程對比，
俺就不公開和NXP“PK”了~~~
//i2c.h
#include "main.h"
#ifndef __LPC11xxI2c_H__
#define __LPC11xxI2c_H__
#ifdef __cplusplus
extern "C" {
#endif
class I2cObj;
class I2cObj {//系統串口類
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];//接收數據緩沖區
};
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;//復位I2C,否則死機
SYSCON.SYSAHBCLKCTRL.Bits.I2CCLK = 1;
//位域寫法
IOCON.PIO0_4.Bits.FUNC    = IOCON_SCL;//選擇PIO0.4為I2C_SCL
IOCON.PIO0_4.Bits.I2CMODE = IOCON_SCL_I2CMODE;//選擇PIO0.4為I2C_SCL
IOCON.PIO0_5.Bits.FUNC    = IOCON_SDA;//選擇PIO0.5為I2C_SCL
IOCON.PIO0_5.Bits.I2CMODE = IOCON_SDA_I2CMODE;//選擇PIO0.5為I2C_SDA
//寄存器寫法
/*
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();//通訊失敗
nVIC.ISER.Bits.I2C_IRQn = 1;
}
void I2cObj::SetAddress(unsigned char I2CAddress)
{
SubAddr = I2CAddress;
}
void I2cObj::Start(void)
{
Busy = true;
   State = I2C_START;//主機準備發送啟始位
   Count = 0;//發送數據個數
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STA);//設置使能起始標志
}
void I2cObj::REStart(void)
{
Busy = true;
   State = I2C_REP_START;//主機準備發送啟始位
   Count = 0;//發送數據個數
I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除標志
I2C0.CONSET.Regs = (1 << I2EN) | (1 << STA);//設置使能起始標志
}
void I2cObj::Stop(void)
{
Busy = false;
State = I2C_BUS_OK;//通訊成功
  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;//通訊失敗
  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();//延時等待寫入完成
}
}
void I2cObj::Exec(void)
{
  switch(I2C0.STAT.Regs & 0xf8) {
    case I2C_START://主機收到自己發送的開始信號
        if (State == I2C_START) {//本次中斷應該接收TW_START信號
          I2C0.DAT.Regs = SubAddr & 0xfe;//發送子機地址(寫)
    State = I2C_MT_SLA_ACK;//Status下次I2C_MT_SLA_ACK
             I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中斷標志
     }
     else Exit();//通訊失敗
        break;
case I2C_REP_START://主機收到自己發送的重新開始信號
        if (State == I2C_REP_START) {//本次中斷應該接收TW_RESTART信號
          I2C0.DAT.Regs = SubAddr | 0x01;//發送子機地址(讀)
       State = I2C_MR_SLA_ACK;//Status下次I2C_MR_SLA_ACK
             I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中斷標志
     }
     else Exit();//通訊失敗
        break;
case I2C_MT_SLA_ACK://主發機接收到從機的地址應答信號后發送命令
        if (State == I2C_MT_SLA_ACK) {//本次中斷應該接收TW_MT_SLA_ACK信號
       State = I2C_MT_DATA_ACK;//Status下次應該收TW_MT_DATA_ACK
             I2C0.DAT.Regs = SubComm;//發送子機命令
             I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中斷標志
     }
     else Exit();//通訊失敗
        break;
case I2C_MR_SLA_ACK://主收機接收到從機的地址應答信號
        if ((State == I2C_MR_SLA_ACK) && SubCount) {//本次中斷應該接收TW_MR_SLA_ACK信號
       State = I2C_MR_DATA_ACK;//Status下次應該收TW_MR_DATA_ACK
             I2C0.CONCLR.Regs = (1 << STA) | (1 << SI);//清除中斷標志,主機轉入接收狀態
    I2C0.CONSET.Bits.AA = 1;
     }
     else Exit();//通訊失敗
     break;
case I2C_MT_DATA_ACK://主收機接收到從機的數據應答信號
        if ((State == I2C_MT_DATA_ACK) && (Count < MainCount)) {//本次中斷應該接收TW_MT_DATA_ACK信號
          I2C0.DAT.Regs = TxBuffer[Count ++];//發送子機數據
             I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中斷標志
     }
     else {
          if ((State == I2C_MT_DATA_ACK) && (Count == MainCount) && (SubAddr & 1)) {//本次中斷應該接收TW_MT_DATA_ACK信號
           REStart();//
    }
             else Stop();//通訊成功
     }
     break;
case I2C_MR_DATA_ACK:
        if ((State == I2C_MR_DATA_ACK) && (Count < SubCount)) {
          RxBuffer[Count ++] = I2C0.DAT.Regs;//接收子機數據
    if (Count < SubCount) {
               I2C0.CONCLR.Regs = (1 << STA) | (1 << SI);//主機轉入接收狀態
      I2C0.CONSET.Bits.AA = 1;
    }
    else {
               I2C0.CONCLR.Regs = (1 << STA) | (1 << SI) | (1 << AA);//清除中斷標志,主機轉入接收狀態
      State = I2C_MR_DATA_NACK;//下次進入I2C_MR_DATA_NACK，接收數據準備完成
    }
     }
     else Exit();//通訊失敗
     break;
case I2C_MR_DATA_NACK://數據接收結束
        if ((State == I2C_MR_DATA_NACK) && (Count == SubCount)) {
       Stop();//通訊成功
     }
     else Exit();//通訊失敗
     break;
// case I2C_MT_DATA_NACK:
//     Exit();//通訊失敗
//     break;
default:
     Exit();//通訊失敗
  }
}
unsigned char I2cObj::ReadByte(unsigned char Address, unsigned char & Data)
{
SubAddr |= 0x01;
MainCount = 0;//發送0個數據(只讀)
//本程序為通用I2C,故發送器件后一般為命令，對EEPROM來說，命令實際是EEPROM地址
SubComm = Address;//讀出地址
SubCount = 1;//接收1個數據
Start();
while (Busy);
if (State == I2C_BUS_OK) {//通訊成功
  Data = RxBuffer[0];//取出一個字節
}
return State;//(讀出數據在RxBuffer[0]~RxBuffer[15])
}
unsigned char I2cObj::WriteByte(unsigned char Address, unsigned char Data)
{
SubAddr &= 0xfe;
MainCount = 1;//發送1個數據
//本程序為通用I2C,故發送器件后一般為命令，對EEPROM來說，命令實際是EEPROM地址
SubComm = Address;//寫入地址
TxBuffer[0] = Data;//寫入數據
SubCount = 0;//接收0個數據
Start();
while (Busy);
if (State == I2C_BUS_OK) {//通訊成功
  PortLed1.DATA.Bits.PinLed1 = 0;//LED1亮
}
return State;
}

//讀LM75
I2c.SetAddress(0x90);//設置LM75器件地址
I2c.WriteByte(1, Data);//寫配置命令1
I2c.ReadByte(0, Data);//讀溫度命令0
Uart.Send(Data);
//讀寫AT24C16
I2c.SetAddress(0xa0);//設置AT24C16器件地址
for (int i = 1; i < 16; i ++)//延時
{
  I2c.WriteByte(i, i);//寫入EEPROM一個字節
  I2c.WriteWait();//延時等待寫入完成
  I2c.ReadByte(i, Data);//讀出EEPROM一個字節
  Uart.Send(Data);
}

HotPower@163.com  2010.9.6 23:58 于雁塔菜地

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