LPC23xx通過I2C接口讀寫AT24C64
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I2C.h
本文引用地址：http://www.ex-cimer.com/article/201611/317227.htm#define AT24C64NW 0xA0
#define AT24C64NR 0xA1
#define MAX_TIMEOUT0x00FFFFFF
#define I2CONSET_I2EN0x00000040 /* I2C Control Set Register */
#define I2CONSET_AA0x00000004
#define I2CONSET_SI0x00000008
#define I2CONSET_STO0x00000010
#define I2CONSET_STA0x00000020
#define I2CONCLR_AAC0x00000004 /* I2C Control clear Register */
#define I2CONCLR_SIC0x00000008
#define I2CONCLR_STAC0x00000020
#define I2CONCLR_I2ENC0x00000040
#define I2DAT_I2C0x00000000 /* I2C Data Reg */
#define I2ADR_I2C0x00000000 /* I2C Slave Address Reg */
#define I2SCLH_SCLH0x00000080 /* I2C SCL Duty Cycle High Reg */
#define I2SCLL_SCLL0x00000080 /* I2C SCL Duty Cycle Low Reg */
#define SDA0 0x08000000 //p0.27
#define SCL0 0x10000000 //p0.28
#define SDA0CON 0x08000000
#define SCL0CON 0x10000000
extern DWORD I2CInit( UINT32 Fi2c );
extern DWORD I2CStart( void );
extern DWORD I2CStop( void );
extern DWORD I2CStartAgain( void );
extern DWORD I2C_ReadByte(BYTE ACK, BYTE *RcvData);
extern DWORD I2C_SendNByte(UINT16 SubAddr ,UINT8 *Data,UINT8 Length);
extern DWORD I2C_ReadNByte(UINT16 SubAddr ,UINT8 *Data,UINT8 Length);
I2C.c
DWORD I2CInit( UINT32 Fi2c )
{
if (Fi2c > 400000)
Fi2c = 400000;
PINSEL1 &= ~0x03C00000;
PINSEL1 |= 0x01400000;/* set PIO0.27 and PIO0.28 to I2C0 SDA and SCK */
I20SCLH = (Fpclk/Fi2c + 1) / 2;/*設(shè)定I2C時(shí)鐘*/
I20SCLL = (Fpclk/Fi2c)/2;
I20CONCLR = 0x2C;// clear STA, SI,AA
I20CONSET = 0x40;// SET I2EN/*使能主I2C */
return( TRUE );
}
DWORD I2CStart( void )
{
DWORD timeout = 0;
DWORD returnValue = FALSE;
/*--- Issue a start condition ---*/
I20CONCLR=I2CONCLR_SIC|I2CONCLR_AAC|I2CONCLR_STAC;
I20CONSET=I2CONSET_STA|I2CONSET_I2EN;/* Set Start flag */
/*--- Wait until START transmitted ---*/
while( 1 )
{
if (I20STAT==0x08)
{
returnValue = TRUE;
break;
}
if ( timeout >= MAX_TIMEOUT )
{
returnValue = FALSE;
break;
}
timeout++;
}
return( returnValue );
}
DWORD I2CStartAgain( void )
{
DWORD timeout = 0;
DWORD returnValue = FALSE;
/*--- Issue a start condition ---*/
I20CONCLR = I2CONCLR_SIC|I2CONCLR_AAC|I2CONCLR_STAC;//發(fā)送重復(fù)起始條件前一定要清零SI
I20CONSET = I2CONSET_STA|I2CONSET_I2EN;/* Set Start flag */
/*--- Wait until START transmitted ---*/
while( 1 )
{
if ( I20STAT == 0x10 )
{
returnValue = TRUE;
break;
}
if ( timeout >= MAX_TIMEOUT )
{
returnValue = FALSE;
break;
}
timeout++;
}
return( returnValue );
}
DWORD I2CStop( void )
{
I20CONSET = I2CONSET_STO;/* Set Stop flag */
I20CONCLR = I2CONCLR_SIC|I2CONCLR_STAC|I2CONCLR_AAC;/* Clear SI flag */// modified
/*--- Wait for STOP detected ---*/
while( I20CONSET & I2CONSET_STO );
return TRUE;
}
void I2C_SendByte(UINT8 SData)
{
I20DAT=SData;
I20CONCLR =0x28;/*清零SI,STA */
while (!(I20CONSET&I2CONCLR_SIC));// wait interrupt flag ( waiting for SI==1)
}
DWORD I2C_SendNByte(UINT16 SubAddr ,UINT8 *Data,UINT8 Length)
{
BYTE i;
I2CStart();
if(I20STAT==0x08)/*已發(fā)送起始條件*/
{
I2C_SendByte(AT24C64NW);// Device Address
if(I20STAT==0x18) /*已發(fā)送SLA+W，已接收ACK */
{
I2C_SendByte((SubAddr>>8)&(0x00FF));
if(I20STAT==0x28)/*已發(fā)送SubAddr_H，已接收ACK */
{
I2C_SendByte(SubAddr&(0x00FF));
if(I20STAT==0x28) /*已發(fā)送SubAddr_L，已接收ACK */
{
for(i=0;i { do{ I2C_SendByte(Data[i]); }while(I20STAT!=0x28); } if(I2CStop()) { DelayNS(5);//10ms return TRUE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; } DWORD I2C_ReadByte(BYTE ACK, BYTE *RcvData) { if (ACK==1)//send ACK { I20CONSET=I2CONSET_AA; } else//sendNOACK if(ACK==0) { I20CONCLR=I2CONCLR_AAC; } I20CONCLR=I2CONCLR_SIC|I2CONCLR_STAC;// clear SISAT while (!(I20CONSET&I2CONCLR_SIC));// wait interrupt flag ( waiting for SI==1) if(ACK==1) { if((I20STAT&0xF8)==0x50) //receive data and get ack { *RcvData=I20DAT; return TRUE; } else return FALSE ; } else if(ACK==0) { if((I20STAT&0xF8)==0x58) //receive data and get NoAck (the last data you want to get) { *RcvData=I20DAT; return TRUE; } else return FALSE ; } return FALSE ; } DWORD I2C_ReadNByte(UINT16 SubAddr ,UINT8 *Data,UINT8 Length) { BYTEi; if (!I2CStart()) { return FALSE; } if(I20STAT==0x08)/*已發(fā)送起始條件*/ { I2C_SendByte(AT24C64NW);// Device Address if(I20STAT==0x18) /*已發(fā)送SLA+W，已接收ACK */ { I2C_SendByte((SubAddr>>8)&(0x00FF)); if(I20STAT==0x28)/*已發(fā)送SubAddr_H，已接收ACK */ { I2C_SendByte(SubAddr&(0x00FF)); if(I20STAT==0x28) /*已發(fā)送SubAddr_L，已接收ACK */ { if (I2CStartAgain())//發(fā)送重復(fù)起始條件切換為主接受模式 { I2C_SendByte(AT24C64NR); if(I20STAT==0x40)/*已發(fā)送SLA+R，已接收ACK*/ { for(i=0;i { if(!(I2C_ReadByte(1,&Data[i]))) { return FALSE; } } if( !( I2C_ReadByte(0, &Data[Length-1]) ) ) //讀最后一個(gè)數(shù)據(jù) { return FALSE; } if (I2CStop())//發(fā)送停止條件 { return TRUE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; } return FALSE; }
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