i2c.c

根据I2C协议传输的源代码

#include <HT86072.H>
#include "Structure.H"
#include "External.H"
#include "Variable.H"

unsigned char ucWatch, ucWatch2, ucWatch3;

void SYSTEM_INITIAL(void)
{
  SPEECH_INITIAL();
	_pac = 0b11111111;  //Input:Bit=1,Output:Bit=0
	_pbc = 0b11110000;
	_pcc = 0b00000011;	
	_tmr1c = 0x80;
	_emi = 1;
	_et0i = 1;
	_et1i = 0;
	_et2i = 1;	
	_et3i = 0;
 
  _tmr2c = 0x90;			//500us Timer
  _tmr2h = 0xFC;
  _tmr2l = 0x18;

	_T1ON = 0;		
	_T2ON = 0;
	_T3ON = 0;	
}

void GameInitial(void)
{
	I2C.uMode.ucValue = 0xE0;
}


unsigned char ucI2CAcc, ucI2CStatus;
								
void INTERRUPT_TIMER1_I2C(void)
{
	#asm
		mov _ucI2CAcc,a
		mov a,[0ah]
		mov _ucI2CStatus,a
	#endasm	
	if (I2C.bPulseBusy == TRUE)				//判断脉冲有没有输出完
		{
			if (I2C.bPulse == HIGH)
				{
					_SCL = LOW;								//SCL输出低电平
					I2C.uMode.bits.bSCL = OUTPUT;
					_I2CPort = I2C.uMode.ucValue;
					
					if (I2C.uSend.bits.bData)
						{
							I2C.uMode.bits.bSDA = INPUT;
							_I2CPort = I2C.uMode.ucValue;
						}
					else
						{
							_SDA = LOW;
							I2C.uMode.bits.bSDA = OUTPUT;
							_I2CPort = I2C.uMode.ucValue;
						}
				}
			else
				{		
					I2C.uMode.bits.bSCL = INPUT;		//SCL输出高电平
					_I2CPort = I2C.uMode.ucValue;
					I2C.bPulseBusy = FALSE;
				}
			I2C.bPulse = ~I2C.bPulse;		//输出脉冲的电平取反		
		}
	#asm
		mov a,_ucI2CStatus
		mov [0ah],a
		mov a,_ucI2CAcc
		reti
	#endasm			
}


void PulseOut(void)
{
	_tmr1l = TIME1_L;		
	_tmr1h = TIME1_H;	//50us:Pulse				
  _T1ON = 1;  
  _et1i = 1;  
 	I2C.bPulse = HIGH;					//输出脉冲的初始化
 	while(I2C.ucPulseNumber != 0)
 		{						
  		I2C.bPulseBusy = TRUE;  		  		
  		while(I2C.bPulseBusy == TRUE)	//等待输出的脉冲
  			{
  				_T1ON = 1;
					_et1i = 1;
  			}
  		I2C.uSend.ucValue <<= 1;		//下一个地址  		
  		//发送8位数据后，需要输出结束位。即SCL输出一个脉冲，并上升沿时，SDA输出高电平
  		I2C.uSend.ucValue |= 0x01;  																	
  		I2C.ucPulseNumber--;
		}	
	_T1ON = 0;
	_et1i = 0;
}

bit SendStart(void)
{
	I2C.uMode.bits.bSCL = INPUT;		//发送Start信号，即在SCL为高电平时，SDA下降沿。
	_I2CPort = I2C.uMode.ucValue;	
	I2C.uMode.bits.bSDA = INPUT;
	_I2CPort = I2C.uMode.ucValue;

  if (_SCL && _SDA)
	{
		_SDA = LOW;            
		I2C.uMode.bits.bSDA = OUTPUT;
		_I2CPort = I2C.uMode.ucValue;
	}
	else
		return ERROR;	
	return OK;
}

bit SendByte(void)
{
	unsigned char i, j;			
	ucWatch3 = I2C.uSend.ucValue; I2C.ucPulseNumber = 9;						//发送信号
	PulseOut();
	
	I2C.uSend.bits.bPrevious = _SCL;
	for(i=0; i<255; i++)							//接收ACK信号
	{
		I2C.uSend.bits.bCurrent = _SCL;		
		if (I2C.uSend.bits.bCurrent && !I2C.uSend.bits.bPrevious)		//读取SCL上升沿时，SDA的值
			{
				if (_SDA == LOW)						
					{
						for(j=0; j<255; j++)	 //收到ACK的上升沿信号，等待Slave放弃总线
						{
							if (_SDA && _SCL)
								return OK;
						}
						ucWatch2 = 0x01; return ERROR;
					}
				else
					{
						ucWatch2 = 0x02; return ERROR;
					}				
			}
		I2C.uSend.bits.bPrevious = I2C.uSend.bits.bCurrent;			
	}
	ucWatch2 = 0x03; return 	ERROR;
}

bit ReceiveByte(void)
{
	unsigned char i;
	unsigned char j;	
	
	I2C.uSend.ucValue = 0x80;						//发送准备信息
	I2C.ucPulseNumber = 1;
	PulseOut();	
	I2C.uReceive.ucValue = 0;
	
	for(i=0; i<8; i++)
	{
		I2C.uSend.bits.bPrevious = _SCL;
		I2C.uReceive.ucValue <<= 1;					//接收下一个BIT
		for(j=0; j<0xFF; j++)
		{
			I2C.uSend.bits.bCurrent = _SCL;
			if (I2C.uSend.bits.bCurrent && !I2C.uSend.bits.bPrevious)		//读取SCL上升沿时，SDA的值
				{
					I2C.uReceive.bits.bData = _SDA;
					break;
				}
			I2C.uSend.bits.bPrevious = I2C.uSend.bits.bCurrent;			
		}
		if (j == 0xFF)
			return ERROR;		
	}
	
	I2C.uSend.bits.bPrevious = _SCL;				//等待结束信号
	for(i=0; i<0xFF; i++)
		{
			I2C.uSend.bits.bCurrent = _SCL;
			if (I2C.uSend.bits.bCurrent && !I2C.uSend.bits.bPrevious)		//读取SCL上升沿时，SDA的值
				{
					if (_SDA == LOW)
						return ERROR;
					else
						break;
				}
			I2C.uSend.bits.bPrevious = I2C.uSend.bits.bCurrent;
		}
	if (i == 0xFF)
		return ERROR;
		
	I2C.ucPulseNumber = 1;							//发送ACK信号
	I2C.uSend.ucValue = 0;
	PulseOut();
	
	I2C.uMode.bits.bSDA = INPUT;				//放弃I2C的发送权力
	_I2CPort = I2C.uMode.ucValue;
	I2C.uMode.bits.bSCL = INPUT;
	_I2CPort = I2C.uMode.ucValue;
	return OK;
}

bit Send(void)
{
	unsigned char i, ucTemp;
	if (SendStart())
		{
			I2C.uSend.ucValue = I2C.ucID << 4;
			I2C.uSend.ucValue |= I2C.ucCommand;
			if (SendByte())
				{
					switch(I2C.ucCommand)
					{
						case DISPLAY:
							for(i=0; i<I2C.ucDataNumber; i++)
							{
								I2C.uSend.ucValue = I2C.ucData[i];
								if (!SendByte())
									{ucWatch = i;break;}
							}
							return OK;
							break;
						case KEYBOARD:
							for(i=0; i<I2C.ucDataNumber; i++)
							{
								if(!ReceiveByte())
									break;
								I2C.ucData[i] = I2C.uReceive.ucValue;
							}
							I2C.uSend.ucValue = 0x80;						//发送准备信息
							I2C.ucPulseNumber = 1;
							PulseOut();								
							return OK;
							break;
					}
					ucWatch = 0xfd;
					return ERROR;
				}
			ucWatch = 0xff; return ERROR;
		}
	ucWatch = 0xfe;return ERROR;	
}

void MAIN(void)
{
	unsigned char ucTemp1, ucTemp2, ucTemp3, ucTemp4;
	unsigned char i1, i2, i3, i4, k,t1,t2;
	unsigned long j, n;
	SYSTEM_INITIAL();
	
	GameInitial();
	k = 0; t1 =0; t2 = 0; ucWatch = 0; ucWatch2 = 0;
	while(1)
	{
		for(j=0, i1=1, i2=2, i3=3, i4=4; j<0xFFFE; j++, i1++, i2+=2, i3+=3, i4+=4)
		{
		I2C.ucID = 1;
		I2C.ucCommand = DISPLAY;
		I2C.ucDataNumber = 4;
		I2C.ucData[0] = i1;
		I2C.ucData[1] = i2;
		I2C.ucData[2] = i3;
		I2C.ucData[3] = i4;		
		ucTemp1 = I2C.ucData[0];
		ucTemp2 = I2C.ucData[1];
		ucTemp3 = I2C.ucData[2];
		ucTemp4 = I2C.ucData[3];		
		if (!Send()) 
			{t1 = 0x1; break;}
		for(n=0; n<0xFFff; n++) ;
		I2C.ucData[0] = 0x00;
		I2C.ucData[1] = 0x00;
		I2C.ucData[2] = 0x00;
		I2C.ucData[3] = 0x00;
		I2C.ucID = 1;
		I2C.ucCommand = KEYBOARD;
		I2C.ucDataNumber = 4;		
		if (!Send())
			{t2 = 0x2; break;}
		ucTemp1 = I2C.ucData[0];
		ucTemp2 = I2C.ucData[1];
		ucTemp3 = I2C.ucData[2];
		ucTemp4 = I2C.ucData[3];			
		if (I2C.ucData[0] != i1)
			{k = 0x1;break;}
		if (I2C.ucData[1] != i2)
			{k = 0x2;break;}
		if (I2C.ucData[2] != i3)
			{k = 0x3;break;}
		if (I2C.ucData[3] != i4)
			{k = 0x4;break;}	
		for(n=0; n<0xFFff; n++) ;				
		}
		if (j != 0xFFFF)
			I2C.ucData[0] = 1;
	}
}