原创 at25f4096驱动程序

https://static.assets-stash.eet-china.com/album/old-resources/2009/7/29/7fa23c9f-aada-4a2d-be9f-2ea9cbb55951.rar       at25f4096驱动程序。通过proteus7.4仿真，可以学习spi接口的时序驱动及程序编写。我用的是avr的芯片，用io口模拟spi的时序。

///////////////////////////////////////////////////////////////////////////////////////

unsigned char SPI_HostReadByte(void) //下降沿
{
    uchar i,RecData = 0;
    for(i=0;i<8;i++)
    {            
        RecData <<= 1;
        if(PINB&0X08)RecData += 1;
                       
        SCK_high;              

        SCK_low; 
 
    } 
    return (RecData);  
}

///////////////////////////////////////////////////////////////////////////////////////

void SPI_HostWriteByte(unsigned char wByte) //上升沿
{
    unsigned char i;
    for(i = 0; i < 8; i++)
    {
    if((wByte << i) & 0x80)
    {
        MOSI_high;
    }
    else
    {
        MOSI_low;
    }
                   
    SCK_high; 

    SCK_low; 
                       

    }     
}

///////////////////////////////////////////////////////////////////////////////////////

在proteus7.4仿真如下：

以下是针对at25f4096的驱动程序：

#include "includes.h"

#define  CS         PB0
#define  SCK      PB1
#define  MOSI    PB2
#define  MISO    PB3

#define SCK_high   PORTB|=BIT(SCK);  DDRB|=BIT(SCK);
#define SCK_low    PORTB&=~BIT(SCK); DDRB|=BIT(SCK);

#define MOSI_high  PORTB|=BIT(MOSI);
#define MOSI_low   PORTB&=~BIT(MOSI);

#define MISO_high  PORTB|=BIT(MISO);
#define MISO_low   PORTB&=~BIT(MISO);

#define CS_high    PORTB|=BIT(CS);
#define CS_low     PORTB&=~BIT(CS); 

/* Instruction Codes */
#define WREN                       0x06
#define WRDI                        0x04
#define RDSR                        0x05
#define WRSR                       0x01
#define READ                        0x03
#define PROGRAM               0x02
#define SECTOR_ERASE     0x52
#define CHIP_ERASE           0x62
#define RDID                        0x15

unsigned char buffer[256];

/******************************************************************************
//void SPI_Init(void)
******************************************************************************/
void SPI_Init(void)
{
    DDRB|=0X07;
    DDRB&=0XF7;
    CS_high;
    SCK_low;
    MOSI_low;
    MISO_high;

}
/******************************************************************************
//unsigned char SPI_HostReadByte(void)
******************************************************************************/
unsigned char SPI_HostReadByte(void) //下降沿
{
/*      
    uchar i,RecData = 0;
    for(i=0;i<8;i++)
    {     
        SCK_low;
        SCK_low; 
                   
        RecData <<= 1;
        if(PINB&0X08)RecData += 1; 
        SCK_high; 
        SCK_high;                               
    } 
     
    return (RecData); 
*/  
 
    uchar i,RecData = 0;
    for(i=0;i<8;i++)
    {            
        RecData <<= 1;
        if(PINB&0X08)RecData += 1;
                       
        SCK_high; 
        SCK_high;                  

        SCK_low;
        SCK_low;       
    } 
    return (RecData);  
 
 
}
/******************************************************************************
//void SPI_HostWriteByte(unsigned char wByte)
******************************************************************************/
void SPI_HostWriteByte(unsigned char wByte) //上升沿
{
/*  unsigned char i;
    for(i = 0; i < 8; i++)
    { 
        SCK_low;
        SCK_low;
          
        if((wByte << i) & 0x80)
            {
            MOSI_high;
        }
        else
        {
            MOSI_low;
        }
                   
        SCK_high;
        SCK_high;                         
    }
 */     
  
    unsigned char i;
    for(i = 0; i < 8; i++)
    {
    if((wByte << i) & 0x80)
    {
        MOSI_high;
    }
    else
    {
        MOSI_low;
    }
                   
    SCK_high;
    SCK_high;
      
    SCK_low;
    SCK_low;                          

    }     
   
}
//=====================================================================================//
//unsigned char read_status_register(void)
//=====================================================================================//
unsigned char read_status_register(void)
{
 unsigned char status;
 CS_low;  
   SPI_HostWriteByte(RDSR);
   status = SPI_HostReadByte();
   CS_high;
 return status;  
}

//=====================================================================================//
//void SPI_WREN()
//写命令使能（很重要，如果忘记写，读状态一直是忙）
//=====================================================================================//
void SPI_WREN()
{
    while((read_status_register()&0x01)==1);//读取状态寄存器,判断是否为忙
           
    CS_low;     
    SPI_HostWriteByte(WREN);
    CS_high;
}
//=====================================================================================//
//unsigned int get_mem_id()
//正常时 i="0x1f"; j="0x64";否则程序出错
//=====================================================================================//
unsigned int get_mem_id()
{
    unsigned int i,j;
 
    while((read_status_register()&0x01)==1);//读取状态寄存器,判断是否为忙
    
    CS_low;                                      /* Enable AT25F512 Chip Select (L) */
    SPI_HostWriteByte(RDID);                     /* transmit the SECTOR_ERASE op_code */
    i="SPI"_HostReadByte();                        /* receive the manufacturing code */
    j= SPI_HostReadByte();                       /* receive the ID code */
    CS_high;                                     /* Disable AT25F512A Chip Select (H) */
    return i+j<<8;  
  
} 

//=====================================================================================//
// void write_status_register(unsigned char status_register)
// Description: Write Status Register (WRSR) 
//=====================================================================================//
void write_status_register(unsigned char status_register)
{
 
    while((read_status_register()&0x01)==1); //读取状态寄存器最高位,判断是否为忙
    SPI_WREN();                              //you must write
    while((read_status_register()&0x01)==1); //读取状态寄存器最高位,判断是否为忙   

    CS_low;          
    SPI_HostWriteByte(WRSR);                                     /* transmit the WRSR op_code */
    SPI_HostWriteByte(status_register); //                       /* transmit the status register value */
    CS_high;
                     
}
//=====================================================================================//
//void program_at25f4096(uint32 address_write_to_4096, uchar *point_to_databuffer, int num_of_data_writeto4096)
//=====================================================================================//
void program_at25f4096(uint32 address_write_to_4096, uchar *point_to_databuffer, int num_of_data_writeto4096)
{

 uchar *pdata_to_be_write = point_to_databuffer; 
        unsigned int i = 0; 
          
        char  data_buffer[3];//last_address_of_4096赋值给data_buffer 高位在前
 data_buffer[0] = (uint8)(address_write_to_4096>>16);
 data_buffer[1] = (uint8)(address_write_to_4096>>8);
 data_buffer[2] = (uint8)address_write_to_4096;       

        while((read_status_register()&0x01)==1); //读取状态寄存器,判断是否为忙           
        SPI_WREN();
        while((read_status_register()&0x01)==1); //读取状态寄存器,判断是否为忙         

        CS_low;
        SPI_HostWriteByte(PROGRAM);          
        SPI_HostWriteByte(data_buffer[0]);
        SPI_HostWriteByte(data_buffer[1]);
        SPI_HostWriteByte(data_buffer[2]);
 for(i=0;i<num_of_data_writeto4096;i++)
 { 
            SPI_HostWriteByte(pdata_to_be_write);
 }
        CS_high;  
}
//=====================================================================================//
//unsigned char read_from_at25f4096(uint32 address_read_from_at25f4096, uint8 *point_to_databuffer, int num_of_data_readfrom4096)
//=====================================================================================//   
void  read_from_at25f4096(uint32 address_read_from_at25f4096, uint8 *point_to_databuffer, int num_of_data_readfrom4096)
{
 int i;
 uint8 *pdata_get_from_4096 = point_to_databuffer;
 char  data_buffer[3];//要读的储存器的首地址赋给data_buffer 高位在前
       
 data_buffer[0] = (uint8)(address_read_from_at25f4096>>16);
 data_buffer[1] = (uint8)(address_read_from_at25f4096>>8);
 data_buffer[2] = (uint8)address_read_from_at25f4096;
       
        while((read_status_register()&0x01)==1);           
        SPI_WREN();
        while((read_status_register()&0x01)==1); 
                  
        CS_low;
        {
        SPI_HostWriteByte(READ);
       
        SPI_HostWriteByte(data_buffer[0]);
        SPI_HostWriteByte(data_buffer[1]);
        SPI_HostWriteByte(data_buffer[2]);