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  • (转)CortexM3 (NXP LPC1788)之EEPROM存储器

    EEPROM是一种非易失性存储器，主要用于存储相对少量的数据，如存储一些系统的配置信息。通过系统的EEPROM控制模块可以轻松的进行EERPOM的存储控制。

            要正确使用EPPROM需要配置掉电寄存器EEPWRDWN确定EEPROM的工作模式，配置EEPROM时钟分频器寄存器，使EPPROM工作在375KHZ。下面对EPPROM的读和写数据进行介绍。

            EEPROM存储器的访问有三种操作方式：读、写、擦除/编程。对EPPROM中写数据分成两个单独的操作：写和擦除/编程。第一步写操作并不是真正把数据写入EPPROM的存储介质中，而只是更新被称作“页寄存器”的临时数据寄存器。只有执行下一步”擦除/编程“操作才会真正地更新非易失存储器。LPC1788共有4K的片内EPPROM，其中EPPROM的每一页等于页寄存器大小为64Byte，总共有64页。大小正好是64*64=4096Byte=4K。首先我们指定的位数，如8、16或者32位，将数据写入页寄存器，页内的地址偏移由EEPROM地址寄存器的第6位决定。如果需要往页寄存器写入一串数据，写完第一个数据后，页内的偏移地址会自动增加，我们只需把要操作的下一个数据填入EEPROM写数据寄存器即可。当页寄存器的64个字节被写满，必须进行编程操作，将数据写入到EEPROM的存储介质。然后更新页寄存器的偏移地址。

            对于EEPROM的读操作，首先要向地址寄存器写入一个12位的地址，高6位为页的偏移，即我们需要读哪个页寄存器。低6位为页内的偏移，即我们需要读当前页的哪个字节。读操作也可以自动的对地址寄存器做后递增，这样就可以对EEPROM存储器进行连续的操作而无需每次读数据都写入一个新地址。

            下面的程序将信息写入EEPROM后读出通过串口打印显示

    [cpp]
    1. #include "LPC1788_REG.h" 
    2. #include "uart.h" 
    3.  
    4. #define rEECMD          (*(volatile unsigned*)(0x00200080)) 
    5. #define rEEADDR         (*(volatile unsigned*)(0x00200084)) 
    6. #define rEEWDATA        (*(volatile unsigned*)(0x00200088)) 
    7. #define rEERDATA        (*(volatile unsigned*)(0x0020008C)) 
    8. #define rEEWSTATE       (*(volatile unsigned*)(0x00200090)) 
    9. #define rEECLKDIV       (*(volatile unsigned*)(0x00200094)) 
    10. #define rEEPWRDWN       (*(volatile unsigned*)(0x00200098)) 
    11.  
    12. #define rEEINTEN        (*(volatile unsigned*)(0x00200FE4)) 
    13. #define rEEINTCLR       (*(volatile unsigned*)(0x00200FD8)) 
    14. #define rEEINTSET       (*(volatile unsigned*)(0x00200FDC)) 
    15. #define rEEINTSTAT      (*(volatile unsigned*)(0x00200FE0)) 
    16. #define rEEINTSTATCLR   (*(volatile unsigned*)(0x00200FE8)) 
    17. #define rEEINTSTATSET   (*(volatile unsigned*)(0x00200FEC)) 
    18.  
    19. #define EEPROM_PAGE_SIZE 64 
    20. void Init_EEPROM(void); 
    21. void Write_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count); 
    22. void Read_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count); 
    23.  
    24. char read_buffer[]; 
    25. char write_buffer[] = {"\n\r\ 
    26. \t - Name: Nuncle.lee \n\r\ 
    27. \t - QQ: 23610603 \n\r\ 
    28. \t - Email: nuncle.lee@gmail.com\n\r"}; 
    29.  
    30. int main(void) 
    31. {    
    32.     Init_Uart2(); 
    33.     Init_EEPROM(); 
    34.      
    35.      
    36.     Write_EEPROM(0, 0, write_buffer, sizeof(write_buffer)); 
    37.     Write_EEPROM(sizeof(write_buffer)/64, sizeof(write_buffer)%64, '\0', 1); 
    38.      
    39.     Read_EEPROM(0, 0, read_buffer, sizeof(write_buffer)+1); 
    40.      
    41.     Uart2SendS(read_buffer); 
    42.  
    43.     return 0; 
    44. } 
    45.  
    46. void Init_EEPROM(void) 
    47. { 
    48.     unsigned int val=0; 
    49.      
    50.     rEEPWRDWN = 0;  //不处于掉电模式 
    51.     rEECLKDIV = (CCLK/375000)-1;    //设置一个375KHZ的EEPROM时钟 
    52.      
    53.     val  = ((((CCLK / 1000000) * 15) / 1000) + 1);      //配置等待状态时间 
    54.     val |= (((((CCLK / 1000000) * 55) / 1000) + 1) << 8); 
    55.     val |= (((((CCLK / 1000000) * 35) / 1000) + 1) << 16); 
    56.     rEEWSTATE = val; 
    57. } 
    58. void Write_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count) 
    59. { 
    60.     unsigned int i; 
    61.      
    62.     rEEADDR = (page_offset&0x3f);   //确定开始写的页内偏移地址 
    63.     for(i=0; i<count; i++) 
    64.     { 
    65.         rEECMD = 0x3;               //8位写操作 
    66.         rEEWDATA = *(data+i); 
    67.         while(!(rEEINTSTAT & (0x1<<26)));   //等待写操作完成 
    68.         page_offset++; 
    69.          
    70.         if(page_offset >= EEPROM_PAGE_SIZE)     //如果当前页写满了64Byte 则启动 编程操作 
    71.         { 
    72.             rEEINTSTATCLR = 0x1<<28; 
    73.             rEEADDR = (page_num&0x3F)<<6; 
    74.             rEECMD = 0x6;   //擦除编程 
    75.             while(!(rEEINTSTAT & (0x1<<28)));   //等待编程完成 
    76.              
    77.             page_offset = 0; 
    78.             page_num++;     //写满一页，准备写下一页 
    79.             rEEADDR = 0;    //写满一页，从页的开始写 
    80.         } 
    81.         elseif(i==count-1)                 //如果要写入EPPROM的数据写完成，启动编程操作 
    82.         { 
    83.             rEEINTSTATCLR = 0x1<<28; 
    84.             rEEADDR = (page_num&0x3F)<<6; 
    85.             rEECMD = 0x6;   //擦除编程 
    86.             while(!(rEEINTSTAT & (0x1<<28))); 
    87.         } 
    88.     } 
    89. } 
    90.  
    91. void Read_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count) 
    92. { 
    93.     unsigned int i; 
    94.     rEEADDR = (page_num&0x3F)<<6|page_offset&0x3F;      //确定读数据的起始位置，包括页偏移和页内的偏移 
    95.     rEECMD = 0x1<<3;                                    //8位读，地址自动递增模式 
    96.     for(i=0; i<count; i++) 
    97.     { 
    98.         while(!(rEEINTSTAT & (0x1<<26)));               //等待上一次读数据完成 
    99.         *(data+i) = rEERDATA; 
    100.         page_offset++; 
    101.          
    102.         if(page_offset >= EEPROM_PAGE_SIZE)             //如果当前页64Byte读完，准备读下一页 
    103.         { 
    104.             page_offset = 0; 
    105.             page_num++; 
    106.             rEEADDR = (page_num&0x3F)<<6|page_offset&0x3F;   
    107.             rEECMD = 0x1<<3; 
    108.         } 
    109.     } 
    110. }  
    #include "LPC1788_REG.h"
#include "uart.h"

#define rEECMD          (*(volatile unsigned*)(0x00200080))
#define rEEADDR         (*(volatile unsigned*)(0x00200084))
#define rEEWDATA        (*(volatile unsigned*)(0x00200088))
#define rEERDATA        (*(volatile unsigned*)(0x0020008C))
#define rEEWSTATE       (*(volatile unsigned*)(0x00200090))
#define rEECLKDIV       (*(volatile unsigned*)(0x00200094))
#define rEEPWRDWN       (*(volatile unsigned*)(0x00200098))

#define rEEINTEN        (*(volatile unsigned*)(0x00200FE4))
#define rEEINTCLR       (*(volatile unsigned*)(0x00200FD8))
#define rEEINTSET       (*(volatile unsigned*)(0x00200FDC))
#define rEEINTSTAT      (*(volatile unsigned*)(0x00200FE0))
#define rEEINTSTATCLR   (*(volatile unsigned*)(0x00200FE8))
#define rEEINTSTATSET   (*(volatile unsigned*)(0x00200FEC))

#define EEPROM_PAGE_SIZE 64
void Init_EEPROM(void);
void Write_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count);
void Read_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count);

char read_buffer[];
char write_buffer[] = {"\n\r\
\t - Name: Nuncle.lee \n\r\
\t - QQ: 23610603 \n\r\
\t - Email: nuncle.lee@gmail.com\n\r"};

int main(void)
{   
    Init_Uart2();
    Init_EEPROM();
    
    
    Write_EEPROM(0, 0, write_buffer, sizeof(write_buffer));
    Write_EEPROM(sizeof(write_buffer)/64, sizeof(write_buffer)%64, '\0', 1);
    
    Read_EEPROM(0, 0, read_buffer, sizeof(write_buffer)+1);
    
    Uart2SendS(read_buffer);

    return 0;
}

void Init_EEPROM(void)
{
    unsigned int val=0;
    
    rEEPWRDWN = 0;  //不处于掉电模式
    rEECLKDIV = (CCLK/375000)-1;    //设置一个375KHZ的EEPROM时钟
    
    val  = ((((CCLK / 1000000) * 15) / 1000) + 1);      //配置等待状态时间
	val |= (((((CCLK / 1000000) * 55) / 1000) + 1) << 8);
	val |= (((((CCLK / 1000000) * 35) / 1000) + 1) << 16);
    rEEWSTATE = val;
}
void Write_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count)
{
    unsigned int i;
    
    rEEADDR = (page_offset&0x3f);   //确定开始写的页内偏移地址
    for(i=0; i<count; i++)
    {
        rEECMD = 0x3;               //8位写操作
        rEEWDATA = *(data+i);
        while(!(rEEINTSTAT & (0x1<<26)));   //等待写操作完成
        page_offset++;
        
        if(page_offset >= EEPROM_PAGE_SIZE)     //如果当前页写满了64Byte 则启动 编程操作
        {
            rEEINTSTATCLR = 0x1<<28;
            rEEADDR = (page_num&0x3F)<<6;
            rEECMD = 0x6;   //擦除编程
            while(!(rEEINTSTAT & (0x1<<28)));   //等待编程完成
            
            page_offset = 0;
            page_num++;     //写满一页，准备写下一页
            rEEADDR = 0;    //写满一页，从页的开始写
        }
        else if(i==count-1)                 //如果要写入EPPROM的数据写完成，启动编程操作
        {
            rEEINTSTATCLR = 0x1<<28;
            rEEADDR = (page_num&0x3F)<<6;
            rEECMD = 0x6;   //擦除编程
            while(!(rEEINTSTAT & (0x1<<28)));
        }
    }
}

void Read_EEPROM(unsigned char page_num, unsigned char page_offset, char* data, unsigned int count)
{
    unsigned int i;
    rEEADDR = (page_num&0x3F)<<6|page_offset&0x3F;      //确定读数据的起始位置，包括页偏移和页内的偏移
    rEECMD = 0x1<<3;                                    //8位读，地址自动递增模式
    for(i=0; i<count; i++)
    {
        while(!(rEEINTSTAT & (0x1<<26)));               //等待上一次读数据完成
        *(data+i) = rEERDATA;
        page_offset++;
        
        if(page_offset >= EEPROM_PAGE_SIZE)             //如果当前页64Byte读完，准备读下一页
        {
            page_offset = 0;
            page_num++;
            rEEADDR = (page_num&0x3F)<<6|page_offset&0x3F;  
            rEECMD = 0x1<<3;
        }
    }
}

     

    程序的执行结果如下图

    程序中，sizeof关键字计算出字符数组的大小，并不包含字符串的结束标志‘\0’。因此还需在sizeof(write_buffer)的位置写入字符串的结束标志。读取时读sizeof(write_buffer)+1个字节，才能正确的通过串口打印数据。当然，也可以自己指定串口打印字符的个数，而不用字符串结束标志去判断。
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  • 原文地址：https://www.cnblogs.com/tdyizhen1314/p/2704601.html
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