AT93C46 SPI接口EEPROM读写程序

//-----------------------函数声明-------------------------------------------------------- 
#include "reg51.h" 
#include "intrins.h" 
//-----------------------管脚声明-----www.pICavr.com------------------------------------- 

sbit CS_93=P1^0; 
sbit CLK_93=P1^1; 
sbit DI_93=P1^2; 
sbit DO_93=P1^3; 
sbit VCC_93=P1^4; 
#define READ_c   0x02 
#define WRITE_c  0x01 
#define ERASE_c  0x03 
#define EWEN_c   0x00 
#define EWDS_c   0x00 
#define ERAL_c   0x00 
#define WRAL_c   0x00 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： delay 
// 入口参数： N 
// 函数功能：延时子程序，实现(16*N+24)us的延时  
// 系统采用11.0592MHz的时钟时,延时满足要求,其它情况需要改动 
//-------------------------------------------------------------------------------------------------- 
  void delay(unsigned  int N)   
  { 
  int i;  
  for(i=0;i  } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： SEND_1 
// 函数功能： 送1位数据"1" 
//-------------------------------------------------------------------------------------------------- 
void SEND_1(void) 
      {  
      DI_93=1;  
      CLK_93=1;  
      _nop_();  
      CLK_93=0; 
      _nop_(); 
      } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： SEND_0 
// 函数功能： 送1位数据"0" 
//-------------------------------------------------------------------------------------------------- 
void SEND_0(void) 
        {  
         DI_93=0;  
         CLK_93=1; 
         _nop_(); 
         CLK_93=0; 
         _nop_(); 
         } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： SEND_0 
// 函数功能： 送1位数据"0" 
//-------------------------------------------------------------------------------------------------- 
void start_operation(unsigned char operation_code) 
        {  
         CS_93=1;  
          SEND_1();                   //起始位 
          if (operation_code&0x02)    //操作码 
          SEND_1();  
          else  
          SEND_0(); 
          if (operation_code&0x01)  
          SEND_1();  
          else  
          SEND_0(); 
         } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： SEND_BYTE 
// 入口参数： dd，待发送的数据 
// 函数功能： 送1BYTE数据 
//-------------------------------------------------------------------------------------------------- 
void SEND_BYTE(unsigned char dd) 
     {  
      unsigned char i;  
      for (i=0;i<8;i++)  
          { 
          if (dd>=0x80) SEND_1();  
          else SEND_0(); 
          dd=dd<<1;  
          } 
     } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： RECEIVE_BYTE 
// 返回值：   dd，待接收的数据 
// 函数功能： 送1BYTE数据 
//-------------------------------------------------------------------------------------------------- 
unsigned char RECEIVE_BYTE(void) 
              { 
              unsigned char i,dd;  
              DO_93=1; 
              for (i=0;i<8;i++)  
              {  
              dd<<=1;  
              CLK_93=1;_nop_(); 
              CLK_93=0;_nop_();  
              if (DO_93) dd|=1;  
              }  
              return(dd); 
             } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： EWEN 
// 函数功能： 擦/写允许指令 
// 捎谠谏系绺次缓螅珹T93CXX首先将处于擦/写不允许状态。 
// 故该指令必须在所有编程模式前执行，一旦该指令执行后， 
// 只要外部没有断电就可以对芯片进行编程。 
//-------------------------------------------------------------------------------------------------- 
void EWEN(void) 
           { 
           _nop_();  
           CS_93=1;  
           start_operation(EWEN_c);  
           SEND_BYTE(0xC0);  
           CS_93=0; 
           } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称：EWDS 
// 函数功能： 擦写截止 
// 使用该指令可对写入的数据进行保护 
//-------------------------------------------------------------------------------------------------- 
void EWDS(void) 
           { 
           _nop_();  
           CS_93=1;  
           start_operation(EWDS_c);  
           SEND_BYTE(0x00);  
           CS_93=0; 
           } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： ERAL 
// 函数功能： 片擦 
// 该指令可将整个存贮器阵列置为1，其它功能与地址擦指令相同 
// 要求VCC = 4.5V to 5.5V。 
//-------------------------------------------------------------------------------------------------- 
void ERAL(void) 
           { 
           _nop_();  
           CS_93=1;  
           start_operation(ERAL_c);  
           SEND_BYTE(0x80);  
           CS_93=0; 
           } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： READ_BYTE 
// 函数功能： 从存储区读一字节数据 
//-------------------------------------------------------------------------------------------------- 
unsigned char READ_BYTE(unsigned char address) 
             {  
             unsigned char dat;  
             CS_93=CLK_93=0; 
             CS_93=1;  
             start_operation(READ_c);  
             SEND_BYTE(address);  
             dat=RECEIVE_BYTE(); 
             CS_93=0; 
             return(dat); 
             } 
//-------------------------------------------------------------------------------------------------- 
// 函数名称： WRITE_BYTE 
// 入口参数： address。dat 
// 返回值：   1或0，表示成功写入 
// 函数功能： 写一字节数据到存储区 
//-------------------------------------------------------------------------------------------------- 
bit WRITE_BYTE(unsigned char address,unsigned char dat) 
                { 
                 unsigned char e,time,temp=address;  
                  e=0;  
                  while (e<3)  
                   { 
                  CS_93=CLK_93=0;  
                  CS_93=1; 
                  EWEN(); 
                  _nop_(); 
                  CS_93=1; 
                  _nop_(); 
                  start_operation(WRITE_c);  
                  SEND_BYTE(address);  
                  SEND_BYTE(dat);  
                  CS_93=0; 
                  _nop_(); 
                  CS_93=1; 
                  time=0; 
                  DO_93=1; 
                  while (1)  
                  { 
                  if (DO_93==1) break; 
                  if (time>20) break; 
                  time++; 
                  }  
                  CS_93=0;  
                 if (READ_BYTE(temp)==dat)  
                    { 
                    return(0); 
                    } 
                    e++; 
                    }  
                    return(1); 
    }