|
void nop()
{
_nop_();
_nop_();
}
/////////24C02讀寫驅(qū)動程序////////////////////
void delay1(unsigned int m)
{ unsigned int n;
for(n=0;n<m;n++);
}
void init() //24c02初始化子程序
{
scl=1;
nop();
sda=1;
nop();
}
void start() //啟動I2C總線
{
sda=1;
nop();
scl=1;
nop();
sda=0;
nop();
scl=0;
nop();
}
void stop() //停止I2C總線
{
sda=0;
nop();
scl=1;
nop();
sda=1;
nop();
}
void writebyte(unsigned char j) //寫一個字節(jié)
{
unsigned char i,temp;
temp=j;
for (i=0;i<8;i++)
{
temp=temp<<1;
scl=0;
nop();
sda=CY; //temp左移時,移出的值放入了CY中
nop();
scl=1; //待sda線上的數(shù)據(jù)穩(wěn)定后,將scl拉高
nop();
}
scl=0;
nop();
sda=1;
nop();
}
unsigned char readbyte() //讀一個字節(jié)
{
unsigned char i,j,k=0;
scl=0; nop(); sda=1;
for (i=0;i<8;i++)
{
nop(); scl=1; nop();
if(sda==1)
j=1;
else
j=0;
k=(k<<1)|j;
scl=0;
}
nop();
return(k);
}
void clock() //I2C總線時鐘
{
unsigned char i=0;
scl=1;
nop();
while((sda==1)&&(i<255))
i++;
scl=0;
nop();
}
////////從24c02的地址address中讀取一個字節(jié)數(shù)據(jù)/////
unsigned char read24c02(unsigned char address)
{
unsigned char i;
start();
writebyte(0xa0);
clock();
writebyte(address);
clock();
start();
writebyte(0xa1);
clock();
i=readbyte();
stop();
delay1(100);
return(i);
}
//////向24c02的address地址中寫入一字節(jié)數(shù)據(jù)info/////
void write24c02(unsigned char address,unsigned char info)
{
start();
writebyte(0xa0);
clock();
writebyte(address);
clock();
writebyte(info);
clock();
stop();
delay1(5000); //這個延時一定要足夠長,否則會出錯。因為24c02在從sda上取得數(shù)據(jù)后,還需要一定時間的燒錄過程。
}
write24c02(0,1);
write24c02(1,2);//24c02的第110到115地址單元作為密碼存儲區(qū)
write24c02(2,3);
write24c02(3,4);
write24c02(4,5);
write24c02(5,6);
password[0]=read24c02(0);
password[1]=read24c02(1);
password[2]=read24c02(2);
password[3]=read24c02(3);
password[4]=read24c02(4);
password[5]=read24c02(5);
|
|