ds1302通信求助帖

ID:1159713 · 發表于 2025-9-1 23:09

本人最近在看江協科技的視頻學習51單片機，但在使用ds1302實時時鐘時遇到了問題：
芯片型號：STC89C52RC
問題描述：在使用ds1302和mcu進行通信時遇到時序問題（大概），具體表現為：在mcu讀取數據之前io口不置0，則通過串口通信接收到的數據總會間隔一個出現一次0x7F（此次通信IO口接收到的一直為1），代碼如下：

main.c文件
#include <REGX52.h>
#include "ds1302.h"
#include "Delay.h"
#include "serial.h"

void main()
{
unsigned char timer = 0x00;
uart_init();

DS1302_Write(0x8E, 0x00);
DS1302_Write(0x80, 0x03);

CE = 0;
Delay_Microsecond(2);
SCLK = 0;
Delay_Microsecond(2);
CE = 1;
Delay_Microsecond(2);

DS1302_Write_Byte(0x81);

while(1)
{
timer = DS1302_Read_Byte() & 0x7F;
uart_transmit(timer);
}
}

ds1302.c文件
#include <REGX52.h>
#include "Delay.h"

sbit SCLK = P3^6;
sbit CE = P3^5;
sbit IO = P3^4;

void DS1302_Write_Byte(unsigned char command)
{
unsigned char i = 0;

for(i = 0; i < 8; i++)
{
IO = command & 0x01;
Delay_Microsecond(2);
SCLK = 0;
Delay_Microsecond(2);
SCLK = 1;

command >>= 1;
}
}

void DS1302_Write(unsigned char command, unsigned char control)
{

CE = 0;
Delay_Microsecond(2);
SCLK = 0;
Delay_Microsecond(2);
CE = 1;
Delay_Microsecond(2);

DS1302_Write_Byte(command);
DS1302_Write_Byte(control);

CE = 0;
}

unsigned char DS1302_Read_Byte()
{
unsigned char i = 0;
unsigned char time = 0x00;

//IO = 0;
for(i = 0; i < 8; i++)
{
SCLK = 1;
Delay_Microsecond(2);
SCLK = 0;
Delay_Microsecond(2);

if(IO)
time |= (0x01 << i);
}

return time;
}

unsigned char DS1302_Read(unsigned char command)
{
unsigned char time = 0x00;

CE = 0;
Delay_Microsecond(2);
SCLK = 0;
Delay_Microsecond(2);
CE = 1;
Delay_Microsecond(2);

DS1302_Write_Byte(command);
time = DS1302_Read_Byte();

CE = 0;
return time;
}

Delay文件
#include "Delay.h"
#include <intrins.h>

void Delay(unsigned int xms) //@11.0592MHz
{
unsigned char data i, j;

while(xms--)
{
_nop_();
i = 2;
j = 199;

do
{
while (--j);
} while (--i);
}

}

void Delay_Microsecond(unsigned char i)
{
while(i--)
_nop_();
}

serial.c文件
#include <regx52.h>
#include "serial.h"

void uart_init()
{
PCON &= 0x0F;
SCON = 0x50;

TMOD &= 0x0F;
TMOD |= 0x20;

TL1 = 0xFD;
TH1 = 0xFD;

EA = 0;
TI = 0;
RI = 0;
TR1 = 1;
}

void uart_transmit(unsigned char byte)
{
SBUF = byte;
while(!TI);
TI = 0;
}

ID:1159713 · 發表于 2025-9-1 23:15

主函數如下：
#include <REGX52.h>
#include "ds1302.h"
#include "Delay.h"
#include "serial.h"

void main()
{
unsigned char timer = 0x00;
uart_init();

DS1302_Write(0x8E, 0x00);
DS1302_Write(0x80, 0x09);

while(1)
{
timer = DS1302_Read(0x81) & 0x7F;
uart_transmit(timer);
}
}

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