msp430 模拟spi实现对flash的读写

hefuzhang · 发表于 2017-5-31 21:37

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#include <msp430.h>
char readdata=0;
char busy_data=0;
void write_byte(char data_byte);
void send_command(char address1,char address2, char address3,char data);// command and address and data
char recive_data(char read_address1, char read_address2,char read_address3);
void delay();
void erase(char command,char erase_address1,char erase_address2,char erase_address3);
void read_busy(void);
int main( void )
{
  // Stop watchdog timer to prevent time out reset

WDTCTL = WDTPW + WDTHOLD;
P2DIR|=BIT5+BIT4+BIT0;       //flsah sck hold cs out
P4DIR|=BIT2+BIT3; //flash  wp si output

P4REN|=BIT1;          // so pull up
P4OUT|=BIT1;          //flash so pullup  selected p4.1
P4OUT|=BIT2;          //wp=1

P6DIR=BIT4;
P6OUT=BIT4;          //led
P2OUT|=BIT0 ; //CS=1;
P2OUT|=BIT5;  //sck=1;
//P2OUT|=BIT4;  // hold =1
_NOP();
_NOP();
P6OUT^=BIT4;
erase(0x20,0x00,0x00,0x00);
read_busy();
send_command(0x00,0x01,0x01,0x00); //xie,mingling
read_busy();
   readdata=recive_data(0x00,0x01,0x01);
while(1)
{
   //  send_command(0x00,0x00,0x00,0x0f); //xie,mingling

   // if(readdata==0x00)
   P6OUT^=BIT4;
   delay();
//  readdata=recive_data(0x00,0x01,0x01);
}

}
void write_byte(char data_byte)
{
char num=0;
for(num=0;num<=7;num++)
{

   if(data_byte&0x80)
   P4OUT|=BIT3 ;             //si=1;
   else
   P4OUT&=~BIT3;             //si=0;
   P2OUT&=~BIT5;          //sck=0;
   _NOP();
   _NOP();
   _NOP();
   _NOP();
      data_byte=data_byte<<1; //数据从高位传输
   P2OUT|=BIT5;       //sck=1;


}
}
void send_command(char address1, char address2 ,char address3 ,char data)
{
  P2OUT|=BIT0 ; //CS=1;
  P2OUT|=BIT5;  //sck=1;
  _NOP();
  P2OUT&=~BIT0 ; //CS=0;
  write_byte(0x06); // write command
  write_byte(address1);
  write_byte(address2);
  write_byte(address3);
  write_byte(data);
  P2OUT|=BIT0 ; //CS=1;
  _NOP();
  _NOP();
  _NOP();
}

char recive_data(char read_address1,char read_address2, char read_address3)
{
char read_data=0;
char num=0;

  P2OUT|=BIT0 ; //CS=1;
  P2OUT|=BIT5;  //sck=1;
  _NOP();
  P2OUT&=~BIT0 ; //CS=0;
  write_byte(0x03);
  write_byte(read_address1);
  write_byte(read_address2);
  write_byte(read_address3);

  for(num=0;num<8;num++)
{
   P2OUT|=BIT5;       //sck=1;
   read_data<<=1;
   _NOP();
   _NOP();
   _NOP();
   _NOP();
   P2OUT&=~BIT5;    //sck=0;
if(P4IN&0x02)
   read_data|=0x01;
else
   read_data&=0xfe;
   _NOP();
   _NOP();
   }
P2OUT|=BIT0 ; //CS=1;
_NOP();
_NOP();
_NOP();
return read_data;


}
void erase(char command,char erase_address1,char erase_address2,char erase_address3)
{
  P2OUT|=BIT0 ; //CS=1;
  P2OUT|=BIT5;  //sck=1;
  _NOP();
  P2OUT&=~BIT0 ; //CS=0;
  write_byte(0x06);
  write_byte(command);
  write_byte(erase_address1);
  write_byte(erase_address2);
  write_byte(erase_address3);
  P2OUT|=BIT0 ; //CS=1;
  _NOP();
  _NOP();
  _NOP();
}
void delay()
{
unsigned  int i=0;
unsigned  int j=0;
for(i=0;i<=500;i++)
   for(j=0;j<=250;j++)
      ;
}
void read_busy()
{
char read_data=0;
char num=0;
P2OUT|=BIT0 ; //CS=1;
P2OUT|=BIT5;  //sck=1;
_NOP();
P2OUT&=~BIT0 ; //CS=0;
write_byte(0x05);       // read the SR1
do{

         for(num=0;num<8;num++)
         {
            P2OUT|=BIT5;       //sck=1;
            _NOP();
            _NOP();
            _NOP();
            _NOP();
            P2OUT&=~BIT5;    //sck=0;
            if(P4IN&0x02)
               read_data|=0x01;
            else
               read_data&=0xfe;
               read_data<<=1;
            }
         _NOP();
         _NOP();
         _NOP();
      busy_data=read_data;
   }
while((busy_data&0x03)!=0x02);
  P2OUT|=BIT0 ; //CS=1;


}

用的单片机是msp430f5438A，模拟spi实现对flash程序的读写，现在读出的数据始终是FF，即应该没有写进数据，那位大神开源指点一二！

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msp430 模拟spi实现对flash的读写

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