spi.c

很好的LF2407对SPI操作的例子

#include    "f2407_c.h"
#define LED port40                           
volatile ioport unsigned int port40;

 
extern unsigned int test_x25650(void); 

void write_enable(void);
unsigned int read_x25650(unsigned int addr);
void write_x25650(unsigned int addr,unsigned int data);
void reset_cs(void);
void set_cs(void);
unsigned int wr_busy(void);
void write_status(void);
void spi_init(void);
 
 
 
void spi_init(void)
{
	unsigned int temp;
	*SPICCR=0x0007;
	*SPICTL=0x0006;
	*SPIBRR=0x001f;
	*SPICCR=*SPICCR|0x0080;
	*SPICCR=0xc7;
	*SPIPRI=0x0030;
	*SPITXBUF=0x5500;
	while((*SPISTS&0x0040)==0);
    temp=*SPIRXBUF;
	  write_enable();
	 write_status();
	
} 

void write_status(void)    /*wpen=1,BL0=BL1=0*/
{
	int temp;
	reset_cs();
	*SPITXBUF=0x0100;
	while((*SPISTS&0x0040)==0);
    temp=*SPIRXBUF;
	*SPITXBUF=0x8000;
	while((*SPISTS&0x0040)==0);
    temp=*SPIRXBUF;
	set_cs();
	while(wr_busy());
}

unsigned int wr_busy(void)
{
	 unsigned int temp;
	 /*for(temp=0;temp<60000;temp++);
	 temp=0;
	 return(temp);*/
	 reset_cs();
	 *SPITXBUF=0x0500; 
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
     *SPITXBUF=0x0000;
     while((*SPISTS&0x0040)==0);
     set_cs();
     temp=*SPIRXBUF;
     temp=temp&0x0001;
     return(temp); 
} 
	 
void set_cs(void)
{
	 /**PCDATDIR=*PCDATDIR|0x0020;*/
	 asm("	setc  XF");
}

void reset_cs(void)
{
	/**PCDATDIR=*PCDATDIR&0xffdf;*/
	asm("	clrc  XF");
}

void write_x25650(unsigned int addr,unsigned int data)
{
	 unsigned temp;
	 write_enable();
	 reset_cs();
	 *SPITXBUF=0x0200;
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
	 *SPITXBUF=addr;
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
     *SPITXBUF=(addr%0x100)*0x100;
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
	 *SPITXBUF=data*0x100;
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
	 set_cs();
	 while(wr_busy());
}
	 
unsigned int read_x25650(unsigned int addr)
{
	unsigned int temp;
	reset_cs();
	*SPITXBUF=0x0300;
	while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
	*SPITXBUF=addr;
	while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
     *SPITXBUF=(addr%0x100)*0x100;
	 while((*SPISTS&0x0040)==0);
     temp=*SPIRXBUF;
	*SPITXBUF=0;
	while((*SPISTS&0x0040)==0);
    temp=*SPIRXBUF;
    set_cs();
    return(temp&0x00ff);
}

/*make X25040 write enable function*/		 
void write_enable(void)
{
	 int temp;
	 reset_cs();
	 *SPITXBUF=0x0600;
	 while((*SPISTS&0x0040)==0);
	 temp=*SPIRXBUF;
	 set_cs();
	 while(wr_busy());
}
	 

/**************************************************************/
/*Ranging from address 0x00 to 0xff,write data 0x55 to each address
/*and test reading from each address. 
/*******************************************************************/   
unsigned int test_x25650(void)
{
	unsigned int data_read;
	unsigned int address;
	spi_init();
	for(address=0;address<0x00ff;address++)
	{
		write_x25650(address,0x55);
		data_read=read_x25650(address);
		/*
		if((address%256)<128)
		{
			LED=0xff77; 
		}
				
		else 
		{
			LED=0xfff7;
			
		}
		*/
		if(data_read!=0x55)  	/*Spi test error*/
		{   
			asm("nop");
			return(0);
			
		} 
		/*write_x25650(address,0xff);*/
	}
	return(1);
}