hal_spi.c

msp430F2xx单片机读写SD卡

{
  USICTL0 = USIPE7+USIPE6+USIPE5+USIMST+USIOE+UCSWRST; // Port, SPI master
  USICKCTL = USISSEL_2 + USICKPL;           // SCLK = SMCLK
  USICTL0 &= ~USISWRST;                     // USI released for operation

  USISRL = 0x00;                            // Ensure SDO low instead of high,
  USICNT = 1;                               // to avoid conflict with CCxxxx
}

#elif SPI_SER_INTF == SER_INTF_BITBANG

void spi_bitbang_out(unsigned char);
unsigned char spi_bitbang_in();
unsigned char spi_bitbang_in_data;

void halSPISetup(void)
{
}

// Output eight-bit value using selected bit-bang pins
void spi_bitbang_out(unsigned char value)
{
  char x;

  for(x=8;x>0;x--)
  {

    if(value & 0x80)                        // If bit is high...
      MMC_PxOUT |= MMC_SIMO;// Set SIMO high...
    else
      MMC_PxOUT &= ~MMC_SIMO;//Set SIMO low...
    value = value << 1;                     // Rotate bits

    MMC_PxOUT &= ~MMC_UCLK; // Set clock low
    MMC_PxOUT |= MMC_UCLK;  // Set clock high
  }
}

// Input eight-bit value using selected bit-bang pins
unsigned char spi_bitbang_in()
{
  char x=0;
  int y;

  for(y=8;y>0;y--)
  {
    MMC_PxOUT &= ~MMC_UCLK; // Set clock low
    MMC_PxOUT |= MMC_UCLK;  // Set clock high

    x = x << 1;                             // Rotate bits
    if(MMC_PxIN & MMC_SOMI)                 // If bit is high...
      x |= 0x01;                            // input bit high
  }
  spi_bitbang_in_data = x;
  return(x);
}
// Input eight-bit value using selected bit-bang pins
unsigned char spi_bitbang_inout(unsigned char value)
{
  char x=0;
  int y;

  for(y=8;y>0;y--)
  {
    if(value & 0x80)                        // If bit is high...
      MMC_PxOUT |= MMC_SIMO;// Set SIMO high...
    else
      MMC_PxOUT &= ~MMC_SIMO;//Set SIMO low...
    value = value << 1;                     // Rotate bits

    MMC_PxOUT &= ~MMC_UCLK; // Set clock low
    MMC_PxOUT |= MMC_UCLK;  // Set clock high

    x = x << 1;                             // Rotate bits
    if(MMC_PxIN & MMC_SOMI)                 // If bit is high...
      x |= 0x01;                            // input bit high
  }
  spi_bitbang_in_data = x;
  return(x);
}
#endif


//Send one byte via SPI
unsigned char spiSendByte(const unsigned char data)
{
  while (halSPITXREADY ==0);    // wait while not ready for TX
  halSPI_SEND(data);            // write
  while (halSPIRXREADY ==0);    // wait for RX buffer (full)
  return (halSPIRXBUF);
}


//Read a frame of bytes via SPI
unsigned char spiReadFrame(unsigned char* pBuffer, unsigned int size)
{
#ifndef withDMA
  unsigned long i = 0;
  // clock the actual data transfer and receive the bytes; spi_read automatically finds the Data Block
  for (i = 0; i < size; i++){
    while (halSPITXREADY ==0);   // wait while not ready for TX
    halSPI_SEND(DUMMY_CHAR);     // dummy write
    while (halSPIRXREADY ==0);   // wait for RX buffer (full)
    pBuffer[i] = halSPIRXBUF;
  }
#else
        U1IFG &= ~(URXIFG1 + URXIFG1);      /* clear flags */
        /* Get the block */
        /* DMA trigger is UART1 receive for both DMA0 and DMA1 */
        DMACTL0 &= ~(DMA0TSEL_15 | DMA1TSEL_15);
        DMACTL0 |= (DMA0TSEL_9 | DMA1TSEL_9);
        /* Source DMA address: receive register.  */
        DMA0SA = U1RXBUF_;
        /* Destination DMA address: the user data buffer. */
        DMA0DA = (unsigned short)pBuffer;
        /* The size of the block to be transferred */
        DMA0SZ = size;
        /* Configure the DMA transfer*/
        DMA0CTL =
          DMAIE   |                         /* Enable interrupt */
          DMADT_0 |                         /* Single transfer mode */
          DMASBDB |                         /* Byte mode */
          DMAEN |                           /* Enable DMA */
          DMADSTINCR1 | DMADSTINCR0;        /* Increment the destination address */

        /* We depend on the DMA priorities here.  Both triggers occur at
           the same time, since the source is identical.  DMA0 is handled
           first, and retrieves the byte.  DMA1 is triggered next, and
           sends the next byte. */
        /* Source DMA address: constant 0xFF (don't increment)*/
        DMA1SA = U1TXBUF_;
        /* Destination DMA address: the transmit buffer. */
        DMA1DA = U1TXBUF_;
        /* Increment the destination address */
        /* The size of the block to be transferred */
        DMA1SZ = count-1;
        /* Configure the DMA transfer*/
        DMA1CTL =
          DMADT_0 |                         /* Single transfer mode */
          DMASBDB |                         /* Byte mode */
          DMAEN;                            /* Enable DMA */

        /* Kick off the transfer by sending the first byte */
        halMMC_SEND(0xFF);
        _EINT(); LPM0;  // wait till done
#endif
  return(0);
}


//Send a frame of bytes via SPI
unsigned char spiSendFrame(unsigned char* pBuffer, unsigned int size)
{
#ifndef withDMA
  unsigned long i = 0;
  unsigned char kd;
  // clock the actual data transfer and receive the bytes; spi_read automatically finds the Data Block
  for (i = 0; i < size; i++){
    while (halSPITXREADY ==0);   // wait while not ready for TX
    halSPI_SEND(pBuffer[i]);     // write
    while (halSPIRXREADY ==0);   // wait for RX buffer (full)
    //pBuffer[i] = halSPIRXBUF;
    kd = halSPIRXBUF;
  }
#else
      /* Get the block */
      /* DMA trigger is UART send */
      DMACTL0 &= ~(DMA0TSEL_15);
      DMACTL0 |= (DMA0TSEL_9);
      /* Source DMA address: the data buffer.  */
      DMA0SA = (unsigned short)pBuffer;
      /* Destination DMA address: the UART send register. */
      DMA0DA = U1TXBUF_;
      /* The size of the block to be transferred */
      DMA0SZ = count;
      /* Configure the DMA transfer*/
      DMA0CTL =
        DMAREQ  |                           /* start transfer */
        DMADT_0 |                           /* Single transfer mode */
        DMASBDB |                           /* Byte mode */
        DMAEN |                             /* Enable DMA */
        DMASRCINCR1 | DMASRCINCR0;          /* Increment the source address */
#endif
  return(0);
}


#ifdef withDMA
#ifdef __IAR_SYSTEMS_ICC__
#if __VER__ < 200
interrupt[DACDMA_VECTOR] void DMA_isr(void)
#else
#pragma vector = DACDMA_VECTOR
__interrupt void DMA_isr(void)
#endif
#endif

#ifdef __CROSSWORKS__
void DMA_isr(void)   __interrupt[DACDMA_VECTOR]
#endif

#ifdef __TI_COMPILER_VERSION__
__interrupt void DMA_isr(void);
DMA_ISR(DMA_isr)
__interrupt void DMA_isr(void)
#endif
{
  DMA0CTL &= ~(DMAIFG);
  LPM3_EXIT;
}
#endif


//---------------------------------------------------------------------
#endif /* _SPILIB_C */