dsp

完整的dsp2407a的spi接口对eeprom x5045操作的接口函数 附详细注释

/*串行EEPROMMAX25045写使能命令*/
void WREN_X5045(void)			/*写使能*/
{
	SPIBUF=RSDR_X5045();
	while ((SPIBUF & 0x01) != 0){SPIBUF=RSDR_X5045();}/*等待内部写结束*/
	PFDATDIR=PFDATDIR | 0x08;	/*取消写保护*/
	TIME(1);
	PFDATDIR=PFDATDIR & 0xFFFB;	/*选择X5045*/
	SPICCR = 0x07;			/*复位上升沿，8位字符长度*/
	SPICTL = 0x0e;			/*有延时，主方式，禁止SPI中断*/
	SPIBRR = 0x13;			/*波特率为1.5MHz*/
	SPIPRI = 0x40;			/*低中断优先级*/
	SPICCR = 0x87;			/*进入工作状态*/
	SPITXBUF = 0X0600;		/*发送写使能命令*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	PFDATDIR=PFDATDIR | 0x0004;	/*清除选择X5045*/
	TIME(1);			/*延时1US*/
}
void WRSR_X5045(unsigned int COM)	/*写状态*/
{
	WREN_X5045();			/*写使能*/
	PFDATDIR=PFDATDIR & 0xFFFB;	/*选择X5045*/
	SPICCR = 0x0F;			/*复位上升沿，15位字符长度*/
	SPICTL = 0x0e;			/*有延时，主方式，禁止SPI中断*/
	SPIBRR = 0x13;			/*波特率为1.5MHz0d*/
	SPIPRI = 0x40;			/*低中断优先级*/
	SPICCR = 0x8f;			/*进入工作状态*/
	SPITXBUF = COM | 0x0100;	/*发送写状态命令*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	PFDATDIR=PFDATDIR | 0x0004;	/*清除选择X5045*/
	PFDATDIR=PFDATDIR & 0xFFF7;	/*写保护*/
}
	/*写EEPROM*//*RA_ADDR为RAM数据首地址，EEP_ADDR为EEP地址，N<4个数8位，H为8选择高地址*/
void WRITE_X5045(unsigned int * RA_ADDR,unsigned int EEP_ADDR,unsigned int N,unsigned int H)
{
	unsigned int I;
	SPIBUF=RSDR_X5045();
	while ((SPIBUF & 0x01) != 0){SPIBUF=RSDR_X5045();}/*等待内部写结束*/
	WREN_X5045();			/*写使能*/
	PFDATDIR=PFDATDIR & 0xFFFB;	/*选择X5045*/
	SPICCR = 0x07;			/*复位上升沿，8位字符长度*/
	SPICTL = 0x0e;			/*有延时，主方式，禁止SPI中断*/
	SPIBRR = 0x13;			/*波特率为1.5MHz*/
	SPIPRI = 0x40;			/*低中断优先级*/
	SPICCR = 0x87;			/*进入工作状态*/
	SPIBUF=((H | 0x02) << 8);
	SPITXBUF = SPIBUF;	/*发送写命令*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	SPITXBUF = (EEP_ADDR << 8);	/*发送地址*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	for (I=0;I<N;I++)
	{
		SPITXBUF =( * (RA_ADDR+I) << 8);	/*发送数据*/
		while (SPISTS == 0){}
		SPIBUF=SPIRXBUF;
		SPISTS=0xFF;			/*清除标志位*/
	}
	PFDATDIR=PFDATDIR | 0x0004;	/*清除选择X5045*/
	PFDATDIR=PFDATDIR & 0xFFF7;	/*写保护*/
}
	/*读EEPROM*//*RA_ADDR为RAM数据首地址，EEP_ADDR为EEP地址，N为字符个数8位，H为8选择高地址*/
void READ_X5045(unsigned int * RA_ADDR,unsigned int EEP_ADDR,unsigned int N,unsigned int H)
{
	unsigned int I;
	SPIBUF=RSDR_X5045();
	while ((SPIBUF & 0x01) != 0){SPIBUF=RSDR_X5045();}/*等待内部写结束*/
	PFDATDIR=PFDATDIR & 0xFFFB;	/*选择X5045*/
	SPICCR = 0x07;			/*复位上升沿，8位字符长度*/
	SPICTL = 0x0e;			/*有延时，主方式，禁止SPI中断*/
	SPIBRR = 0x13;			/*波特率为1.0MHz*/
	SPIPRI = 0x40;			/*低中断优先级*/
	SPICCR = 0x87;			/*进入工作状态*/
	SPITXBUF = (H | 0x03) << 8;	/*发送读命令*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	SPITXBUF = EEP_ADDR << 8;	/*发送地址*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	for (I=0;I<N;I++)
	{
		SPITXBUF = 0;		/*发送伪数据*/
		while (SPISTS == 0){}
		*(RA_ADDR+I) = SPIRXBUF & 0xff;
		SPISTS=0xFF;		/*清除标志位*/
	}
	PFDATDIR=PFDATDIR | 0x0004;	/*清除选择X5045*/
}
	/*读状态寄存器*/
unsigned int RSDR_X5045(void)
{
	TIME(1);
	PFDATDIR=PFDATDIR & 0xFFFB;	/*选择X5045*/
	SPICCR = 0x07;			/*复位上升沿，8位字符长度*/
	SPICTL = 0x0e;			/*有延时，主方式，禁止SPI中断*/
	SPIBRR = 0x13;			/*波特率为1.0MHz*/
	SPIPRI = 0x40;			/*低中断优先级*/
	SPICCR = 0x87;			/*进入工作状态*/
	SPITXBUF =0x0500;		/*发送读命令*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	SPITXBUF = 0;			/*发送伪数据*/
	while (SPISTS == 0){}
	SPIBUF=SPIRXBUF;
	SPISTS=0xFF;			/*清除标志位*/
	PFDATDIR=PFDATDIR | 0x0004;	/*清除选择X5045*/
	return SPIBUF;
}