At45DB161B.c

//******************************************************************************

// MSP430F2274 Interface to AT45DB161B

//

// Uses Texas Instruments eZ430-RF2500 Development Tool with 16MBit ATMEL Flash 

// Memory. Wireless connection not used.

//

//******************************************************************************

// CONSTANTS

#define XTAL 16000000L

#define TICKSPERMS (XTAL / 1000 / 5 - 1)

#define TICKSPERUS (TICKSPERMS / 1000)

// LIBRARIES

#include "msp430x22x4.h"

// PORT DEFINITIONS

#define PORT_CSB_OUT P4OUT

#define PORT_CSB_DIR P4DIR

#define PORT_SPI_DIR P3DIR

#define PORT_SPI_SEL P3SEL

// REGISTER AND FLAG DEFINITIONS

#define TX_BUFFER UCB0TXBUF

#define RX_BUFFER UCB0RXBUF

#define IRQ_REG IFG2

#define RX_IFG UCB0RXIFG

#define TX_IFG UCB0TXIFG

#define SPI_CTL0 UCB0CTL0

#define SPI_CTL1 UCB0CTL1

#define SPI_BR0 UCB0BR0

#define SPI_BR1 UCB0BR1

// Control Register setup

#define STATUS_REGISTER_READ 0x57

#define BUFFER_1_WRITE 0x84  // buffer 1 write 

#define BUFFER_2_WRITE 0x87  // buffer 2 write 

#define BUFFER_1_READ 0x54  // buffer 1 read

#define BUFFER_2_READ 0x56  // buffer 2 read

// PIN DEFINITIONS

#define PIN_RES BIT4 //not connected yet (set to high manually)

#define PIN_CSB BIT3 //not connected yet (set to high manually)

#define PIN_MOSI BIT1

#define PIN_MISO BIT2

#define PIN_SCK BIT3

// FUNCTION PROTOTYPES

void wait_ms(unsigned short ms);

void wait_us(unsigned short us);

unsigned char Read_Status(void);

void main(void)

{

  int i=0;

  unsigned char string [20] ;

  WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

  BCSCTL1 = CALBC1_16MHZ; // Set DCO to calibrated 16MHz

  DCOCTL = CALDCO_16MHZ;

  BCSCTL2 |= DIVS_3; // SMCLK to 2 MHz

  PORT_CSB_DIR |= PIN_CSB;

  PORT_CSB_OUT |= PIN_CSB; // Unselect acceleration sensor

  PORT_SPI_SEL |= PIN_MOSI | PIN_MISO | PIN_SCK; // P3.3,2,1 USCI_B0 option select

  PORT_SPI_DIR |= BIT0; // P3.0 output direction

// Initialize SPI interface to acceleration sensor

  SPI_CTL0 |= UCSYNC | UCMST | UCMSB | UCCKPH; // SPI master, 8 data bits, MSB first,

// clock idle low, data output on falling edge

  SPI_CTL1 |= UCSSEL1; // SMCLK as clock source

  SPI_BR0 = 0x08; // Low byte of division factor for baud rate (250 kHz)

  SPI_BR1 = 0x00; // High byte of division factor for baud rate

  SPI_CTL1 &= ~UCSWRST; // Start SPI hardware

  wait_us(44); // 11 * tsck

  while(i<20)

  {

    string[i++]=Read_Status();

    wait_us(44);

  }

}

// wait ms

void wait_ms(unsigned short ms)

{

  unsigned short a, b;

  for (a = ms; a > 0; a--) // outer loop takes 5 ck per round

  for (b = TICKSPERMS; b > 0; b--) // inner loop takes 5 ck per round

    asm("nop");

}

// wait us

void wait_us(unsigned short us)

{

  unsigned short a;

  us *= TICKSPERUS;

  for (a = us; a > 0; a--) // loop takes 5 ck per round

    asm("nop");

}

void write_SPI(unsigned char spi_data)  //SPI_Mode 3

{

    TX_BUFFER = spi_data; 

    while (!(IRQ_REG & TX_IFG));

}

unsigned char Read_Status(void)  // lesen von ADDR1 

{

  unsigned char retval;    // Rückgabewert;

  //CS_0;            // select EEPROM, CS = 0;

  write_SPI(STATUS_REGISTER_READ);

  write_SPI(0x00);

        write_SPI(0x00);

        write_SPI(0x00);

        write_SPI(0x00);

  //CS_1;             // deselect EEPROM, CS = 1;

  wait_ms(10);

  retval = RX_BUFFER;

  return retval;

}