[SOLVED] eeprom read problem with msp430f6779

[ud23]

hi all i m working with the msp430f6779 and external eeprom i used sample I2c code i am able to write eeprom but when i try to read more then one address its give me garbage value.



i am using 1 k pull -up for sda and scl and scl is 100khz.

below is my code

#include "msp430.h"
#include "I2Croutines.h"

int PtrTransmit;
unsigned char I2CBufferArray[50];
unsigned char I2CBuffer;

 int tx_byte_count;
    unsigned char rx_byte_count;
    int tx_byte_counter;
    unsigned char rx_byte_counter;
    unsigned char i;
    unsigned char tx_rx;
int tx_count;


void InitI2C(unsigned char eeprom_i2c_address)
{
    I2C_PORT_SEL |= SDA_PIN + SCL_PIN;        // Assign I2C pins to USCI_B0

  // Recommended initialisation steps of I2C module as shown in User Guide:
 
                                           
    UCB1CTLW0 |= UCSWRST;                             // Enable SW reset
    UCB1CTLW0 |= UCMST | UCMODE_3 | UCSSEL_3;         // I2C Master, use SMCLK

    UCB1BR0= 12;                                  // fSCL = SMCLK/12 = ~100kHz
    UCB1BR1 = 0;
    UCB1I2CSA = eeprom_i2c_address;                                  // Slave Address is 048h
  // UCB1I2COA1 = 0x01A5;
    UCB1CTLW0 &= ~UCSWRST;                            // Clear SW reset, resume operation
    UCB1IE |= UCTXIE0;                                // Enable TX interrupt                                       // defines the control byte that is
    UCB1IE |= UCRXIE0;                                                  // sent to the EEPROM.
 
  if (UCB1STAT & UCBBUSY)                   // test if bus to be free
  {                                         // otherwise a manual Clock on is
                                            // generated
    I2C_PORT_SEL &= ~SCL_PIN;               // Select Port function for SCL
    I2C_PORT_OUT &= ~SCL_PIN;               //
    I2C_PORT_DIR |= SCL_PIN;                // drive SCL low
    I2C_PORT_SEL |= SDA_PIN + SCL_PIN;      // select module function for the
                                            // used I2C pins
  }
}

/*---------------------------------------------------------------------------*/
// Description:
//   Initialization of the I2C Module for Write operation.
/*---------------------------------------------------------------------------*/
void I2CWriteInit(void)
{
  UCB1CTLW0 |= UCTR;                         // UCTR=1 => Transmit Mode (R/W bit = 0)
  UCB1IFG &= ~UCTXIFG0;
  UCB1IE &= ~UCRXIE0;                         // disable Receive ready interrupt
  UCB1IE |= UCTXIE0;                          // enable Transmit ready interrupt
}

/*----------------------------------------------------------------------------*/
// Description:
//   Initialization of the I2C Module for Read operation.
/*----------------------------------------------------------------------------*/
void I2CReadInit(void)
{
  UCB1CTLW0 &= ~UCTR;                        // UCTR=0 => Receive Mode (R/W bit = 1)
  UCB1IFG &= ~UCRXIFG0;
  UCB1IE  &= ~UCTXIE0;                         // disable Transmit ready interrupt
  UCB1IE  |= UCRXIE0;                          // enable Receive ready interrupt
}
 

  
/*----------------------------------------------------------------------------*/
// Description:
//   Byte Write Operation. The communication via the I2C bus with an EEPROM
//   (2465) is realized. A data byte is written into a user defined address.
/*----------------------------------------------------------------------------*/
void EEPROM_ByteWrite(unsigned int Address, unsigned char Data)
{
  unsigned char adr_hi;
  unsigned char adr_lo;

  while (UCB1STAT & UCBUSY);                // wait until I2C module has
                                            // finished all operations.

  adr_hi = Address >> 8;                    // calculate high byte
  adr_lo = Address & 0xFF;                  // and low byte of address

  I2CBufferArray[2] = adr_hi;               // Low byte address.
  I2CBufferArray[1] = adr_lo;               // High byte address.
  I2CBufferArray[0] = Data;
   tx_count =2;
 //tx_byte_count = tx_count + 1;
 //tx_byte_counter = tx_count; 
 
   I2CWriteInit();
   UCB1CTLW0 |= UCTXSTT;                      // start condition generationemain in LPM0 until all data is TX'd
  __bis_SR_register(LPM0_bits + GIE);      // Enter LPM0 w/ interrupts
   
  // UCB1CTLW0 |= UCTR | UCTXSTT;                                         // => I2C communication is started

 UCB1CTLW0 |= UCTXSTP;                      // I2C stop condition
 // __bis_SR_register(LPM0_bits + GIE); 
 while(UCB1CTLW0 & UCTXSTP);            // Ensure stop condition got sent
}

/*----------------------------------------------------------------------------*/
// Description:
//   Random Read Operation. Data is read from the EEPROM. The EEPROM
//   address is defined with the parameter Address.
/*----------------------------------------------------------------------------*/

unsigned char EEPROM_RandomRead(unsigned int Address)
{
  unsigned char adr_hi;
  unsigned char adr_lo;
  I2CBuffer =0;

  while (UCB1STAT & UCBUSY);                // wait until I2C module has
                                            // finished all operations

  adr_hi = Address >> 8;                    // calculate high byte
  adr_lo = Address & 0xFF;                  // and low byte of address

  I2CBufferArray[1] = adr_hi;               // store single bytes that have to
  I2CBufferArray[2] = adr_lo;  
   tx_count =1;  
 // tx_byte_count = tx_count + 1;
 // tx_byte_counter = tx_count;  
 
   I2CWriteInit();
   UCB1CTLW0 |= UCTXSTT;                      // start condition generationemain in LPM0 until all data is TX'd
  __bis_SR_register(LPM0_bits + GIE);      // Enter LPM0 w/ interrupts
   
  
  // Read Data byte
  I2CReadInit();

  UCB1CTLW0 |= UCTXSTT;                      // I2C start condition
 
  while(UCB1CTLW0 & UCTXSTT);                // Start condition sent? // Enter LPM0 w/ interrupts
   __bis_SR_register(LPM0_bits + GIE);
  UCB1CTLW0 |= UCTXSTP;                      // I2C stop condition
  while(UCB1CTLW0 & UCTXSTP);                // Ensure stop condition got sent
  return I2CBuffer;
}



/*----------------------------------------------------------------------------*/
// Description:
//   Acknowledge Polling. The EEPROM will not acknowledge if a write cycle is
//   in progress. It can be used to determine when a write cycle is completed.
/*----------------------------------------------------------------------------*/
void EEPROM_AckPolling(void)
{
  while (UCB1STAT & UCBUSY);                // wait until I2C module has
                                            // finished all operations
  do
  {
    UCB1STAT = 0x00;                        // clear I2C interrupt flags
    UCB1CTLW0 |= UCTR;                       // I2CTRX=1 => Transmit Mode (R/W bit = 0)
    UCB1CTLW0 &= ~UCTXSTT;
    UCB1CTLW0 |= UCTXSTT;                    // start condition is generated
    while(UCB1CTLW0 & UCTXSTT)               // wait till I2CSTT bit was cleared
    {
      if(!(UCNACKIFG & UCB1STAT))           // Break out if ACK received
        break;
    }
    UCB1CTLW0 |= UCTXSTP;                    // stop condition is generated after
                                            // slave address was sent => I2C communication is started
    while (UCB1CTLW0 & UCTXSTP);             // wait till stop bit is reset
    __delay_cycles(500);                    // Software delay
  }while(UCNACKIFG & UCB1STAT);
}
unsigned char EEPROM_CurrentAddressRead(void)
{
  while(UCB1STAT & UCBUSY);                 // wait until I2C module has
                                            // finished all operations
  I2CReadInit();

 UCB1CTLW0 |= UCTXSTT;                      // I2C start condition
  while(UCB1CTLW0 & UCTXSTT);                // Start condition sent?
 UCB1CTLW0 |= UCTXSTP;                      // I2C stop condition
  __bis_SR_register(LPM0_bits + GIE);       // Enter LPM0 w/ interrupts
  while(UCB1CTLW0 & UCTXSTP);                // Ensure stop condition got sent
  return I2CBuffer;
}


#pragma vector = USCI_B1_VECTOR
__interrupt void USCI_B1_ISR(void)

{
  if(UCTXIFG0 & UCB1IFG)
  {

          UCB1TXBUF = I2CBufferArray[tx_count];         // Load TX buffer
             tx_count--;                  //Decrement TX byte counter
         
          if(tx_count < 0)
          {
               UCB1IE  &= ~UCTXIE0;  
             UCB1IFG &= ~UCTXIFG0;                  //Clear USCI_B0 TX int flag
              __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
          }

  } 
   else if(UCRXIFG0 &  UCB1IFG)
  {
               I2CBuffer = UCB1RXBUF;        // store received data in buffer
              // UCB1IFG &= ~UCRXIFG0;      
        __bic_SR_register_on_exit(LPM0_bits);   // Exit LPM0
       }
}

please any one help me whats the problem exactly in above code.

 

[bigdogguru]

What is the make and model of the external EEPROM?

BigDog

 

[ud23]

its atmel mack 24co2 epprom