#include<reg52.h>
#include<intrins.h>
#define I2CDelay() {_nop_();_nop_();_nop_();_nop_();}
sbit I2C_SCL = P2^0;
sbit I2C_SDA = P2^1;
void I2CStart()
{
I2C_SDA = 1;
I2C_SCL = 1;
I2CDelay();
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 0;
}
void I2CStop()
{
I2C_SCL = 0;
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SDA = 1;
I2CDelay();
}
bit I2CWrite(unsigned char dat)
{
bit ack;
unsigned char mask;
for(mask=0x80;mask!=0;mask>>=1)
{
if((mask&dat) == 0)
I2C_SDA = 0;
else
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
ack = I2C_SDA;
I2CDelay();
I2C_SCL = 0;
return (~ack);
}
unsigned char I2CReadNAK()
{
unsigned char mask;
unsigned char dat;
I2C_SDA = 1;
for(mask=0x80;mask!=0;mask>>=1)
{
I2CDelay();
I2C_SCL = 1;
if(I2C_SDA == 0)
dat &= ~mask;
else
dat |= mask;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;
return dat;
}
unsigned char I2CReadACK()
{
unsigned char mask;
unsigned char dat;
I2C_SDA = 1;
for(mask=0x80;mask!=0;mask>>=1)
{
I2CDelay();
I2C_SCL = 1;
if(I2C_SDA == 0)
dat &= ~mask;
else
dat |= mask;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;
return dat;
}
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