#include "intrins.h"
#include "comm.h"
#define uchar unsigned char
#define uint unsigned int
#define OP_READ 0xa1
#define OP_WRITER 0xa0
extern void Delay(unsigned int n);
sbit SDA_24CXX =P2^5;
sbit SCL_24CXX =P2^6;
void start_i2c(void)
{
SDA_24CXX = 1;
SCL_24CXX = 1;
_nop_();
_nop_();
SDA_24CXX = 0;
_nop_();
_nop_();
SCL_24CXX = 0;
}
void stop_i2c(void)
{
SDA_24CXX = 0;
SCL_24CXX = 1;
_nop_();
_nop_();
SDA_24CXX = 1;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
}
bit send_byte_24cxx(uchar str)
{
uchar BitCnt;
uchar ack;
for(BitCnt=0;BitCnt<8;BitCnt++)
{
if((str<<BitCnt)&0x80)
SDA_24CXX = 1;
else
SDA_24CXX = 0;
SCL_24CXX = 1;
_nop_();
_nop_();
_nop_();
_nop_();
SCL_24CXX = 0;
}
SDA_24CXX = 1;
SCL_24CXX = 1;
_nop_();
_nop_();
_nop_();
_nop_();
ack = SDA_24CXX;
SCL_24CXX = 0;
return ack;
}
uchar rcv_byte_24cxx(void)
{
uchar retc;
uchar BitCnt;
retc=0;
SDA_24CXX = 1;
for(BitCnt=0;BitCnt<8;BitCnt++)
{
SCL_24CXX = 0;
_nop_();
_nop_();
_nop_();
_nop_();
SCL_24CXX = 1;
retc=retc<<1;
if(SDA_24CXX == 1)retc=retc+1;
}
SCL_24CXX = 0;
return(retc);
}
void ack_i2c(bit a)
{
if(a==0)SDA_24CXX = 0;
else SDA_24CXX = 1;
SCL_24CXX = 1;
_nop_();
_nop_();
_nop_();
_nop_();
SCL_24CXX = 0;
}
unsigned char read_byte(unsigned char add)
{uchar temp;
start_i2c();
if(send_byte_24cxx(OP_WRITER) != 0)
return 0;
if(send_byte_24cxx(add) != 0)
return 0;
start_i2c();
if(send_byte_24cxx(OP_READ) != 0)
return 0;
temp = rcv_byte_24cxx();
ack_i2c(1);
stop_i2c();
return temp;
}
unsigned char write_byte(unsigned char add,unsigned char str)
{
start_i2c();
if(send_byte_24cxx(OP_WRITER) != 0)
return 1;
if(send_byte_24cxx(add) != 0)
return 1;
if(send_byte_24cxx(str) != 0)
return 1;
stop_i2c();
return 0;
}
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