MSP430F2013 SPI

#include "SPI.h"

#include <stdlib.h>

//------------------------------------------------------------------------------

void spiInit(void)

{

  // Configure SPI Pins

  P1DIR |= BIT6 | BIT5;   // MOSI (P1.6) and SCK (P1.5) output

  P1DIR &= ~BIT7;         // MISO (P1.7) input

  P1SEL |= BIT5 + BIT6 + BIT7;

  // USI SPI setup

  USICTL0 |= USISWRST;

  USICTL1 = USICKPH;                // USICKPH=1 means sampling is done on the

                                    // leading edge of the clock

  USICKCTL = USISSEL_2 | USIDIV_0;  // Clock source = SMCLK/1

  USICTL0 = USIPE7 |  // SDI/SDA port enable. Input in SPI mode

            USIPE6 |  // SDO/SCL port enable. Output in SPI mode

            USIPE5 |  // SCLK port enable. Output in SPI master mode.

            USIMST |  // Master mode

            USIOE;    // Data output enable

  USICTL0 &= ~USISWRST;

  USISR = 0x0000;

}

//------------------------------------------------------------------------------

uint8_t spiByte(uint8_t data)

{

  USISRL = data;

  USICNT = 8;            // Start SPI transfer

  while (!(USICTL1 & USIIFG));

  return USISRL;

}

//------------------------------------------------------------------------------

void *spiData(void *data, uint16_t size)

{

  if(data == NULL)   // Check for NULL pointer

    return NULL;

  uint8_t *data_ptr = data;

  while(size--)

  {

    *data_ptr = spiByte(*data_ptr) & 0xFF;

    data_ptr++;

  }

  return data;

}

//------------------------------------------------------------------------------

void spiWriteData(const void *data, uint16_t size)

{

  if(data == NULL)   // Check for NULL pointer

    return;

  const uint8_t *data_ptr = data;

  while(size--)

    spiByte(*data_ptr++);

}