spi.c

51单片机模拟spi串行接口程序

sbit CS=P3^5; 

sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}
sbit CLK= P1^5;

sbit DataI=P1^7; 

sbit DataO=P1^6;

#define SD_Disable() CS=1 //片选关 

#define SD_Enable() CS=0 //片选开 

unsigned char SPI_TransferByte(unsigned char val)

{ 

unsigned char BitCounter;

for(BitCounter=8; BiCounter!=0; BitCounter--)

{ CLK=0;

DataI=0; // write

if(val&0x80) DataI=1;

val<<=1; 

CLK=1;

if(DataO)val|=1; // read

} 

CLK=0; 

return val;

}