LPC1768 SSP0驱动示例——SD卡驱动

在STM32的SPI驱动上移植过来的，由于代码较长，这里只提供关键代码：

/* SSPxSR - bit definitions. */
#define TFE     0x01
#define TNF     0x02
#define RNE     0x04
#define RFF     0x08
#define BSY     0x10

/*******************************************************************************
* Function Name  : _spi_read_write
* Description    : None
* Input          : - data:
* Output         : None
* Return         : None
* Attention		 : None
*******************************************************************************/
__inline uint8_t _spi_read_write(uint8_t dat)
{
	/* Write and Read a byte on SPI interface. */
  LPC_SSP0->DR = dat;
  while (LPC_SSP0->SR & BSY);                 /* Wait for transfer to finish */
  return (LPC_SSP0->DR);                      /* Return received value       */
}


/*******************************************************************************
* Function Name  : MSD_SPI_Configuration
* Description    : SD Card SPI Configuration
* Input          : None
* Output         : None
* Return         : None
* Attention		 : None
*******************************************************************************/
void MSD_SPI_Configuration(void)
{					
	/* Initialize and enable the SSP Interface module. */
//	LPC_SC->PCONP       |= (1 << 21);           /* Enable power to SSPI0 block */
	
	/* P3.26 is SD Card Power Supply Enable Pin */
	LPC_GPIO3->FIODIR   |=  (1<<26);            /* P3.26 is output             */
	LPC_GPIO3->FIOPIN   &= ~(1<<26);            /* set P3.26 low(enable power) */

	/* SCK, MISO, MOSI are SSP pins. */
//	LPC_PINCON->PINSEL3 &= ~(3<<8);          /* P1.20 cleared               */
	LPC_PINCON->PINSEL3 |=  (3<<8);          /* P1.20 SCK0                  */
//	LPC_PINCON->PINSEL3 &= ~((3<<14) | (3<<16));  /* P1.23, P1.24 cleared        */
	LPC_PINCON->PINSEL3 |=  ((3<<14) | (3<<16));  /* P1.23 MISO0, P1.24 MOSI0    */
	
	/* SSEL is GPIO, output set to high. */
	LPC_GPIO1->FIODIR   |=  (1<<21);            /* P1.21 is output             */
	LPC_GPIO1->FIOPIN   |=  (1<<21);            /* set P1.21 high (SSEL inact.)*/
	LPC_PINCON->PINSEL3 &= ~(3<<10);            /* P1.21 SSEL (used as GPIO)   */

//	LPC_SC->PCLKSEL1 &= ~(3<<10);               /* PCLKSP0 = CCLK/4 ( 25MHz)   */
//	LPC_SC->PCLKSEL1 |=  (1<<10);               /* PCLKSP0 = CCLK   (100MHz)   */

	LPC_SSP0->CPSR = 50; 						//25M/50
	//LPC_SSP0->CPSR = 250;                       /* 100MHz / 250 = 400kBit      */
												/* maximum of 18MHz is possible*/    
	LPC_SSP0->CR0  = (7<<0)|(3<<6);             /* 8Bit, CPOL=1, CPHA=1        */
	LPC_SSP0->CR1  = 0x0002;                    /* SSP0 enable, master         */
}

/*******************************************************************************
2019年2月27日18:39:50:经过调试发现最小是58,低于这个值就会返回FR_DISK_ERR
*******************************************************************************/
void MSD_SPIHighSpeed(uint8_t on)
{
	/* Set a SPI clock speed to desired value. */

	if (on==1) {
		/* Max. 12 MBit used for Data Transfer. */
		LPC_SSP0->CPSR = 14;                      /* 100MHz/10 = 10MBit  经过测试我手上的卡最大是1.724MBit       */
		printf("MSD_SPIHighSpeed(1)\n");
	}
	else {
		/* Max. 400 kBit used in Card Initialization. */
		LPC_SSP0->CPSR = 50;                     /* 100MHz / 250 = 400kBit      */
		printf("MSD_SPIHighSpeed(0)\n");
	}
}


//测试代码
	FRESULT res;

	res=f_mount(0,&fs);
	if(res==FR_OK)
	{
		printf("f_mount() FR_OK\n");
	}
	else
	{
		printf("f_mount()=%d\n",res);
	}
	res = f_open(&fsrc , "0:/system.txt" , FA_CREATE_ALWAYS|FA_WRITE);
	if(res==FR_OK)
	{
		printf("f_open() FR_OK\n");
		res = f_write(&fsrc,"这个是sd卡驱动测试,hello!",sizeof("这个是sd卡驱动测试,hello!")-1, &WriteSize); 
		f_close(&fsrc);
		printf("f_write()=%d\n",res);
	}
	else
	{
		printf("f_open()=%d\n",res);
	}