24c02.lst

单片机中EEPROM（24C02）的驱动程序

C51 COMPILER V6.12  24C02                                                                  06/27/2005 11:08:45 PAGE 1   


C51 COMPILER V6.12, COMPILATION OF MODULE 24C02
OBJECT MODULE PLACED IN .\24C02.OBJ
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE .\24C02.C DEBUG OBJECTEXTEND

stmt level    source

   1          
   2          
   3          #include <reg51.h>
   4          #include <intrins.h>
   5          
   6          #define	OP_READ	0xa1		// 器件地址以及读取操作
   7          #define	OP_WRITE 0xa0		// 器件地址以及写入操作
   8          #define	MAX_ADDR 0x7f		// AT24C02最大地址
   9          
  10          unsigned char code dis_code[] = {0x7e,0xbd,0xdb,0xe7,0xdb,0xbd,0x7e,0xff};
  11          				// 写入到AT24C01的数据串
  12          
  13          sbit SDA = P3^4;
  14          sbit SCL = P3^3;
  15          
  16          
  17          void start();
  18          void stop();
  19          unsigned char shin();
  20          bit shout(unsigned char write_data);
  21          unsigned char read_random(unsigned char random_addr);
  22          void write_byte( unsigned char addr, unsigned char write_data);
  23          void fill_byte(unsigned char fill_data);
  24          void delayms(unsigned char ms);
  25          
  26          main(void)
  27          {
  28   1      	unsigned char i;
  29   1      	SDA = 1;
  30   1      	SCL = 1;
  31   1      	fill_byte(0xff);		// 全部填充0xff
  32   1      
  33   1      	for(i = 0 ; i < 8; i++)		//写入显示代码到AT24Cxx
  34   1      	{
  35   2      		write_byte(i, dis_code[i]);
  36   2      	}
  37   1      
  38   1      	i = 0;
  39   1      	while(1)
  40   1      	{
  41   2      
  42   2      		P0 = read_random(i);	// 循环读取24Cxx内容，并输出到P0口
  43   2      		i++;
  44   2      		i &= 0x07;		// 循环读取范围为0x00～0x07
  45   2      		delayms(250);
  46   2      	}
  47   1      }
  48          
  49          void start()
  50          // 开始位
  51          {
  52   1      	SDA = 1;
  53   1      	SCL = 1;
  54   1      	_nop_();
  55   1      	_nop_();
C51 COMPILER V6.12  24C02                                                                  06/27/2005 11:08:45 PAGE 2   

  56   1      	SDA = 0;
  57   1      	_nop_();
  58   1      	_nop_();
  59   1      	_nop_();
  60   1      	_nop_();
  61   1      	SCL = 0;
  62   1      }
  63          
  64          void stop()
  65          // 停止位
  66          {
  67   1      	SDA = 0;
  68   1      	_nop_();
  69   1      	_nop_();
  70   1      	SCL = 1;
  71   1      	_nop_();
  72   1      	_nop_();
  73   1      	_nop_();
  74   1      	_nop_();
  75   1      	SDA = 1;
  76   1      }
  77          
  78          unsigned char shin()
  79          // 从AT24Cxx移入数据到MCU
  80          {
  81   1      	unsigned char i,read_data;
  82   1      	for(i = 0; i < 8; i++)
  83   1      	{
  84   2      		SCL = 1;
  85   2      		read_data <<= 1;
  86   2      		read_data |= (unsigned char)SDA;
  87   2      		SCL = 0;
  88   2      	}
  89   1      	return(read_data);
  90   1      }
  91          bit shout(unsigned char write_data)
  92          // 从MCU移出数据到AT24Cxx
  93          {
  94   1      	unsigned char i;
  95   1      	bit ack_bit;
  96   1      	for(i = 0; i < 8; i++)		// 循环移入8个位
  97   1      	{
  98   2      		SDA = (bit)(write_data & 0x80);
  99   2      		_nop_();
 100   2      		SCL = 1;
 101   2      		_nop_();
 102   2      		_nop_();
 103   2      		SCL = 0;
 104   2      		write_data <<= 1;
 105   2      	}
 106   1      	SDA = 1;			// 读取应答
 107   1      	_nop_();
 108   1      	_nop_();
 109   1      	SCL = 1;
 110   1      	_nop_();
 111   1      	_nop_();
 112   1      	_nop_();
 113   1      	_nop_();
 114   1      	ack_bit = SDA;
 115   1      	SCL = 0;
 116   1      	return ack_bit;			// 返回AT24Cxx应答位
 117   1      }
C51 COMPILER V6.12  24C02                                                                  06/27/2005 11:08:45 PAGE 3   

 118          
 119          void write_byte(unsigned char addr, unsigned char write_data)
 120          // 在指定地址addr处写入数据write_data
 121          {
 122   1      	start();
 123   1      	shout(OP_WRITE);
 124   1      	shout(addr);
 125   1      	shout(write_data);
 126   1      	stop();
 127   1      	delayms(10);		// 写入周期
 128   1      }
 129          
 130          void fill_byte(unsigned char fill_data)
 131          // 填充数据fill_data到EEPROM内
 132          {
 133   1      	unsigned char i;
 134   1      	for(i = 0; i < MAX_ADDR; i++)
 135   1      	{
 136   2      		write_byte(i, fill_data);
 137   2      	}
 138   1      
 139   1      }
 140          
 141          unsigned char read_current()
 142          // 在当前地址读取
 143          {
 144   1      	unsigned char read_data;
 145   1      	start();
 146   1      	shout(OP_READ);
 147   1      	read_data = shin();
 148   1      	stop();
 149   1      	return read_data;
 150   1      }
 151          
 152          unsigned char read_random(unsigned char random_addr)
 153          // 在指定地址读取
 154          {
 155   1      	start();
 156   1      	shout(OP_WRITE);
 157   1      	shout(random_addr);
 158   1      	return(read_current());
 159   1      }
 160          
 161          void delayms(unsigned char ms)	
 162          // 延时子程序
 163          {
 164   1      	unsigned char i;
 165   1      	while(ms--)
 166   1      	{
 167   2      		for(i = 0; i < 120; i++);
 168   2      	}
 169   1      }


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    246    ----
   CONSTANT SIZE    =      8    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----       3
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----       1
C51 COMPILER V6.12  24C02                                                                  06/27/2005 11:08:45 PAGE 4   

END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)