单片机驱动实时时钟芯片S35390A读取时间有误求分析附程序 -

#include <stdio.h>
#include <reg52.h>
#include <35390.h>
//#include <S-35390A.h>
void InitUART(void)//使用定时器1作为串口波特率发生器
{
TH1 = 0xFD; //晶振11.0592mhz 波特率设为9600
TL1 = TH1;
TMOD |= 0x20; //定时器1方式2
SCON = 0x50; //串口接收使能
ES = 1; //串口中断使能
TR1 = 1; //定时器1使能
TI = 1; //发送中断标记位，必须设置
}
//毫秒延时函数
void delay_ms(unsigned int t)
{
unsigned char a,b;
while(t--)
{
for(b=102;b>0;b--)
for(a=3;a>0;a--);
}
}
void main()
{
InitUART(); //初始化串口
EA = 1; //开总中断
Write_S35390A();//初始化时间
while(1)
{
Read_S35390A();//读取时间
printf("S35390A[0]=%02BX\r\nS35390A[1]=%02BX\r\nS35390A[2]=%02BX\r\n",S35390A[0],S35390A[1],S35390A[2]);
printf("S35390A[3]=%02BX\r\nS35390A[4]=%02BX\r\nS35390A[5]=%02BX\r\n",S35390A[3],S35390A[4],S35390A[5]);
}
}
35390.h
#define Uchar unsigned char
#define Uint unsigned int
unsigned char S35390A[6]={0x16,0x0C,0x17,0x0E,0x24,0x00};// 22-12-23 14:36:00
sbit IIC_SCL = P2^3;
sbit IIC_SDA = P2^2;
void delayms(Uint n)
{
Uint i,j;
for(i=n;i>0;i--)
{
for(j=750;j>0;j--)
{
}
}
}
/*****************************************
I2c Wait
Wait for some time to get proper I2C timing
******************************************/
void IICWait(void)
{
unsigned int i=10;//i=5;
while(i--);
}
/*****************************************
i2c start
condition SDA 1-0 while SCL=1
******************************************/
void IICStart(void)
{
IIC_SDA=1;
IIC_SCL=1;
IICWait();
IIC_SDA=0;
IICWait();
IIC_SCL=0;
IICWait();
}
/*****************************************
I2c sotp
condition SDA=0-1 while SCL=1
******************************************/
void IICStop(void)
{
IIC_SDA=0;
IICWait();
IIC_SCL=1;
IICWait();
IIC_SDA=1;
IICWait();
}
/*****************************************
35390 Init
Initialize I2C interface
Release I2c BUS
****************************************
void S35390_Init(void)
{
IIC_SDA=1;
IIC_SCL=1;
IIC_Wait();
}
/*****************************************
I2c SentByte
master transfer data to slave and return acknowledge bit
don't include<intrins.h>
******************************************/
bit IICSentByte(unsigned char bytedata)
{
unsigned char i;
bit ack;
for(i=0;i<8;i++)
{
if(bytedata & 0x80)
IIC_SDA=1;
else
IIC_SDA=0;
bytedata<<=1;
IICWait();
IIC_SCL=1;
IICWait();
IIC_SCL=0;
IICWait();
}
IIC_SDA=1; //释放数据总线，等待应答
IICWait();
IIC_SCL=1; //等待数据线的ACK（时钟信号一般上升沿有效）
IICWait();
ack=IIC_SDA;
IIC_SCL=0;
IICWait();
return ack;
}
/*****************************************
I2c ReceiveByte
slave trransfer data to master
******************************************/
unsigned char IICReceiveByte(void)
{
unsigned char i;
unsigned char bytedata=0;
IIC_SCL=0;
IICWait();
for(i=0;i<8;i++)
{
IIC_SCL=1;
IICWait();
bytedata=bytedata<<1;
if(IIC_SDA==1)
{
bytedata = bytedata|0x01;
}
IICWait();
IIC_SCL=0;
IICWait();
}
return bytedata;
}
/*****************************************
I2c SendAcknowledge
Master send acknowledge bit to slave
acknowledge="0",non-acknowledge="1"
******************************************/
void SendAck(bit ack)
{
IIC_SDA=ack;
IIC_SCL=1;
IICWait();
IIC_SCL=0;
}
unsigned char Exchange_highlow(unsigned char car)
{
unsigned i,c=0;
for(i=0;i<8;i++)
{c=c*2+(car-2*(car>>1));car=car>>1;}
return c;
}
void Write_S35390A(void)
{
unsigned char car;
IICStart(); //Send start signal
IICSentByte(0x60); //Send identifer IIC address,状态寄存器1
IICSentByte(0xe0); //reset 0xe0
IICStop();
delayms(10); // Delay a period of time to write
IICStart(); //Send start signal
IICSentByte(0x61); //Send identifer IIC address,状态寄存器1
IICStop();
car=IICReceiveByte();
if(car)
{
car^=0xff;
}
IICStart(); //Send start signal
IICSentByte(0x68); //Send identifer IIC address,INT1
IICSentByte(0x08); //16Hz
IICStop();
IICStart(); //Send start signal
IICSentByte(0x62); //Send identifer IIC address,状态寄存器2
IICSentByte(0x80); //INT1频率输出
IICStop();
IICStart(); //Send start signal
IICSentByte(0x6C); //Send identifer IIC address,时钟较正
IICSentByte(0x86); //较正值
IICStop();
// Send repeated start signal
S35390A[0]=Exchange_highlow(S35390A[0]);
S35390A[1]=Exchange_highlow(S35390A[1]);
S35390A[2]=Exchange_highlow(S35390A[2]);
S35390A[3]=Exchange_highlow(S35390A[3]);
S35390A[4]=Exchange_highlow(S35390A[4]);
IICStart(); // Send start signal
IICSentByte(0x64); // Send identifer IIC address
IICSentByte(S35390A[0]); //year
IICSentByte(S35390A[1]); //month
IICSentByte(S35390A[2]); //day
IICSentByte(0); //week;
IICSentByte(S35390A[3]); //hour
IICSentByte(S35390A[4]); //min
IICSentByte(0); //second
IICStop();
}
void Read_S35390A(void)
{
unsigned char car;
IICStart(); // Send start signal
IICSentByte(0x65); // Send identifer IIC address
// Send repeated start signal
car=IICReceiveByte();S35390A[0]=Exchange_highlow(car); //year
car=IICReceiveByte();S35390A[1]=Exchange_highlow(car); //mon
car=IICReceiveByte();S35390A[2]=Exchange_highlow(car); //day
car=IICReceiveByte(); //week;
car=IICReceiveByte();S35390A[3]=Exchange_highlow(car); //hour
*(&S35390A[3])=*(&S35390A[3])&0x3f; //???
car=IICReceiveByte();S35390A[4]=Exchange_highlow(car); //min
car=IICReceiveByte();S35390A[5]=Exchange_highlow(car); //second
IICStop();
}

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