ds1302 数字时钟

这是在ABC_PN板上做NIOS2实验，基于DS1302的数字时钟。不过这次还没有用到其他模块，直接是将时间通过JTAG_UART读回到PC机上显示的。下面将帖出在NIOS2中读写DS1302的函数，希望对大家有用哦！！

 

开发环境：quartus2 10.1 sp1 ,  nios2 10.1 sp1, nios2 command shell 10.1

系统基本环境： 为了配合DS1302这个慢速设备，所以系统时钟设为了20Mhz

/* DS1302 READ,WRITE,SET REGISER,READ TIME REGISTER
 * ds1302.h
 *
 *  Created on: 2012-2-26
 *  Author: williamhuawu
 */

#ifndef DS1302_H_
#define DS1302_H_
#include <system.h>
#include <io.h>

#define uchar unsigned char

void Delay(int m)
{
 short i;
 short j;
 for(i=0;i<m;i++)
  for(j=0;j<500;j++)
   ;
}
//write one byte into ds1302
void ds1302_byte_write(uchar wdata)
{
 uchar i;
 IOWR(T_DATA_BASE,1,1);
 for(i=0;i<8;i++)
 {
  if((wdata&0x01) == 1)
   IOWR(T_DATA_BASE,0,1);
  else
   IOWR(T_DATA_BASE,0,0);
  IOWR(T_CLK_BASE,0,1);
  Delay(1);
  IOWR(T_CLK_BASE,0,0);
  wdata >>= 1;
 }
}
//read one byte from ds1302
uchar ds1302_byte_read(void)
{
 uchar i,rdata;
 IOWR(T_DATA_BASE,1,0);
 for(i=0;i<8;i++)
 {
  Delay(1);
  rdata >>= 1;
  if(IORD(T_DATA_BASE,0))
   rdata+=0x80;
  IOWR(T_CLK_BASE,0,1);
  Delay(1);
  IOWR(T_CLK_BASE,0,0);
 }
 return rdata;
}
//set one register of ds1302
void ds1302_write_register(uchar register_addr, uchar wdata)
{
 IOWR(T_CLK_BASE,0,0);
 IOWR(T_CE_BASE,0,0);                        //very import procedure
 IOWR(T_CE_BASE,0,1);
 ds1302_byte_write(register_addr);
 ds1302_byte_write(wdata);
 IOWR(T_CLK_BASE,0,1);
 IOWR(T_CE_BASE,0,0);
}
//read one register of ds1302
uchar ds1302_read_register(uchar register_addr)
{
 uchar rd_data_tmp;
 IOWR(T_CLK_BASE,0,0);
 IOWR(T_CE_BASE,0,0);
 IOWR(T_CE_BASE,0,1);
 ds1302_byte_write(register_addr);
 rd_data_tmp = ds1302_byte_read();
 IOWR(T_CLK_BASE,0,1);
 IOWR(T_CE_BASE,0,0);
 return rd_data_tmp;
}
//set ds1302's 7 time register by burst mode
void ds1302_time_burst_write(char write_time_table[])
{
 uchar i ;
 IOWR(T_CLK_BASE,0,0);
 IOWR(T_CE_BASE,0,0);                        //very import procedure
 IOWR(T_CE_BASE,0,1);
 ds1302_byte_write(0xbe);
    for(i=0;i<8;i++) {
     ds1302_byte_write(write_time_table[i]);
    }
    IOWR(T_CLK_BASE,0,1);
    IOWR(T_CE_BASE,0,0);
}
//read 7 time regiser value by burst mode
void ds1302_time_burst_read(char read_time_table[] ) {          // 返回指针的函数
 uchar i ;
 IOWR(T_CLK_BASE,0,0);
 IOWR(T_CE_BASE,0,0);                        //very import procedure
 IOWR(T_CE_BASE,0,1);
 ds1302_byte_write(0xbf);
    for(i=0;i<8;i++) {
    read_time_table[i] = ds1302_byte_read() ;
    }
    IOWR(T_CLK_BASE,0,1);
    IOWR(T_CE_BASE,0,0);
}
// transfer the bcd format time into ascii format to display on the lcd screen
void ds1302_time_bcd2ascii(char *read_time_table,char time_table_ascii[]) {
 time_table_ascii[0] = ((*read_time_table)&0x0f) + 48 ;
 time_table_ascii[1] = (((*read_time_table) >> 4)&0x07) + 48 ;
 time_table_ascii[2] = ((*(read_time_table+1))&0x0f) + 48 ;
 time_table_ascii[3] = (((*(read_time_table+1)) >> 4)&0x07) + 48 ;
 time_table_ascii[4] = ((*(read_time_table+2))&0x0f) + 48 ;
 time_table_ascii[5] = (((*(read_time_table+2)) >> 4)&0x03) + 48 ;
 time_table_ascii[6] = ((*(read_time_table+3))&0x0f) + 48 ;
 time_table_ascii[7] = (((*(read_time_table+3)) >> 4)&0x03) + 48 ;
 time_table_ascii[8] = ((*(read_time_table+4))&0x0f) + 48 ;
 time_table_ascii[9] = (((*(read_time_table+4)) >> 4)&0x01) + 48 ;
 time_table_ascii[10] = ((*(read_time_table+5))&0x07) + 48 ;
 time_table_ascii[11] = ((*(read_time_table+6))&0x0f) + 48 ;
 time_table_ascii[12] = (((*(read_time_table+6)) >> 4)) + 48 ;
}
#endif /* DS1302_H_ */