I2C ISR come only once in MSP430F6779A

Hi Dennis,

Please look into the code.

thanks

#include <msp430.h>

int PtrTransmit,again = 1;
unsigned char I2CBufferArray[66];
unsigned char I2CBuffer;

void UCS_config();
void I2C_config();
void EEPROM_ByteWrite(unsigned int, unsigned char);

void main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop WDT

UCS_config();
I2C_config();

__bis_SR_register(GIE);

EEPROM_ByteWrite(0x0800, 0x12);

__delay_cycles(10000);

for(;;)
{

}
}

void UCS_config(void)
{
PMMCTL0_H = 0xA5;
PMMCTL0_L = 0x03;
UCSCTL0 = UCSCTL0 | 0x1F00;
UCSCTL1 = UCSCTL1 & 0x0000;
UCSCTL1 = UCSCTL1 | 0x0040;
UCSCTL2 = UCSCTL2 & 0x0000 ; // FLL Divider
UCSCTL2 = UCSCTL2 | 0x304F ; // for 20 MHz MCLK and 2.6 MHz SMCLK
UCSCTL3 = 0x0000;

UCSCTL4 = UCSCTL4 & 0X0000;
UCSCTL4 = UCSCTL4 | 0X0043;

P1SEL0 = P1SEL0 | 0X34;
// P1SEL1 = P1SEL1 & 0XCB;
P1DIR = P1DIR | 0X34;
// CPBD = 0X00;
}

void I2C_config(void)
{
// Setup P2.5 UCB0SCL, P2.6 UCB0SDA
P2SEL0 |= BIT5 | BIT6; // Set P2.5,P2.6 to UCB0SCL, UCB0SDA

// Setup eUSCI_B0

UCB0CTLW0 |= UCSWRST; // Enable SW reset
UCB0CTLW0 |= UCMST | UCMODE_3 | UCSSEL_2; // I2C Master, use SMCLK

UCB0BRW_L = 6; // fSCL = SMCLK/12 = ~100kHz
UCB0BRW_H = 0;
UCB0I2CSA = 0x0000; // Slave Address is 00h
UCB0I2COA0 = 0x0001; // I2C Own address
UCB0CTLW0 &= ~UCSWRST; // Clear SW reset, resume operation
// UCB0IE |= UCTXIE0; // Enable TX interrupt
// TXData = 0xAF; // Holds TX data
}

void I2CWriteInit(void)
{
UCB0CTL1 |= UCTR; // UCTR=1 => Transmit Mode (R/W bit = 0)
UCB0IFG &= ~UCTXIFG;
UCB0IE &= ~UCRXIE0; // disable Receive ready interrupt
UCB0IE |= UCTXIE0; // enable Transmit ready interrupt
}

void EEPROM_ByteWrite(unsigned int Address, unsigned char Data)
{
unsigned char adr_hi;
unsigned char adr_lo;

while (UCB0STAT & 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;
PtrTransmit = 2; // set I2CBufferArray Pointer

I2CWriteInit();
UCB0CTL1 |= UCTXSTT; // start condition generation
// => I2C communication is started
__bis_SR_register(GIE); // Enter LPM0 w/ interrupts LPM0_bits |
// UCB0CTL1 |= UCTXSTP; // I2C stop condition
// while(UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent

}

//------------------------------------------------------------------------------
// The USCIAB0_ISR is structured such that it can be used to transmit any
// number of bytes by pre-loading TXByteCtr with the byte count.
//------------------------------------------------------------------------------
// USCI_B0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B0_VECTOR))) USCI_B0_ISR (void)
#else
#error Compiler not supported!
#endif
{
if(UCB0IV == USCI_I2C_UCTXIFG0) // TXIFG0
{
UCB0TXBUF = I2CBufferArray[PtrTransmit];// Load TX buffer
PtrTransmit--; // Decrement TX byte counter
// UCB0IFG &= ~UCTXIFG; // Clear USCI_B0 TX int flag

temp1 = UCB0IE;
temp2 = UCB0IFG;

if(PtrTransmit < 0)
{
UCB0IE &=~UCTXIE0; // disable interrupts.
UCB0CTL1 |= UCTXSTP; // I2C stop condition
again =1;
PtrTransmit = 2;

while(UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
}
}
}

Hi,

Any one looked into this?

waiting for someone help.

Regards

Bhavdipsinh

Hi,

Is there not any TI Employee who responsible to guide.

I need inputs from TI member for it.

Regards

Bhavdipsinh

Please look into attached waveform where blue line shows clock and yellow line shows data. this is come only once.

Please guide.

No one from TI has idea for solution. I have Pull-up data and clock pin of I2C. all other configuration and code is in previous post.

Regards

Bhavdipsinh

Hi Deitmar,

Thanks for your reply and suggestion.

I check below attached code for I2C write (use MSPWare example), change slave address to 0x00h (As per my EEPROM address).

Still same, ISR comes only once and code doesnot work properly.

I am using EEPROM of ST M24C16-W.

waiting for your reply.

Regards

Bhavdipsinh

//
//   E. Chen
//   Texas Instruments Inc.
//   January 2014
//   Built with CCS Version: 5.5.0 and IAR Embedded Workbench Version: 5.52
//******************************************************************************
#include <msp430.h>

unsigned char TXData;
unsigned char TXByteCtr;

void main(void)
{
    WDTCTL = WDTPW | WDTHOLD;                         // Stop WDT

    // Setup P2.5 UCB0SCL, P2.6 UCB0SDA
    P2SEL0 |= BIT5 | BIT6;                             // Set P2.5,P2.6 to UCB0SCL, UCB0SDA

    // Setup eUSCI_B0
    UCB0CTLW0 |= UCSWRST;                             // Enable SW reset
    UCB0CTLW0 |= UCMST | UCMODE_3 | UCSSEL_2;         // I2C Master, use SMCLK

    UCB0BRW_L = 12;                                   // fSCL = SMCLK/12 = ~100kHz
    UCB0BRW_H = 0;
    UCB0I2CSA = 0x00;                                 // Slave Address is 000h
    UCB0CTLW0 &= ~UCSWRST;                            // Clear SW reset, resume operation
    UCB0IE |= UCTXIE0;                                // Enable TX interrupt
    TXData = 0x01;                                    // Holds TX data

    while (1)
    {
        TXByteCtr = 1;                                // Load TX byte counter

        while (UCB0CTLW0 & UCTXSTP) ;                 // Ensure stop condition got sent
        UCB0CTLW0 |= UCTR | UCTXSTT;                  // I2C TX, start condition

        __bis_SR_register(LPM0_bits | GIE);           // Enter LPM0 w/ interrupts
        __no_operation();                             // Remain in LPM0 until all data
                                                      // is TX'd

        TXData++;                                     // Increment data byte
    }
}

//------------------------------------------------------------------------------
// The USCIAB0_ISR is structured such that it can be used to transmit any
// number of bytes by pre-loading TXByteCtr with the byte count.
//------------------------------------------------------------------------------
// USCI_B0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B0_VECTOR))) USCI_B0_ISR (void)
#else
#error Compiler not supported!
#endif
{
    switch (__even_in_range(UCB0IV, 30))
    {
        case USCI_NONE: break;                        // No interrupts
        case USCI_I2C_UCALIFG: break;                 // ALIFG
        case USCI_I2C_UCNACKIFG: break;               // NACKIFG
        case USCI_I2C_UCSTTIFG: break;                // STTIFG
        case USCI_I2C_UCSTPIFG: break;                // STPIFG
        case USCI_I2C_UCRXIFG3: break;                // RXIFG3
        case USCI_I2C_UCTXIFG3: break;                // TXIFG3
        case USCI_I2C_UCRXIFG2: break;                // RXIFG2
        case USCI_I2C_UCTXIFG2: break;                // TXIFG2
        case USCI_I2C_UCRXIFG1: break;                // RXIFG1
        case USCI_I2C_UCTXIFG1: break;                // TXIFG1
        case USCI_I2C_UCRXIFG0: break;                // RXIFG0
        case USCI_I2C_UCTXIFG0:                       // TXIFG0
            if (TXByteCtr)                            // Check TX byte counter
            {
                UCB0TXBUF = TXData;                   // Load TX buffer
                TXByteCtr--;                          // Decrement TX byte counter
            }
            else
            {
                UCB0IFG &= ~UCTXIFG;                  // Clear USCI_B0 TX int flag
                UCB0CTL1 |= UCTXSTP;                  // I2C stop condition
                __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
            }
            break;
        case USCI_I2C_UCBCNTIFG: break;               // CNTIFG
        case USCI_I2C_UCCLTOIFG: break;               // LTOIFG
        case USCI_I2C_UCBIT9IFG: break;               // BIT9IFG
        default: break;
    }
}

Hi Dietmar,

Thanks for your prompt reply.

I checked this code with my 2 different prototype boards and have same behavior.

Yes, It stay in LPM mode. but It goes once in I2C ISR then stuck at LPM.

Please find attached screen shot of debug which shows both situations.

Regards

Bhavdipsinhd

Thanks Dietmar for your reply and guidance.

Please find below attached screen shots in which I take status, Interrupt Enable and Interrupt Flag resisters values at different instants sequential.

I think which help you to give your best solutions.

Thanks and Regards

Bhavdipsinh

Hi Dietmar,

I have enable Ack interrupt and debug code but result is same.

Please find herewith attached sequences screenshots and Waveform of CLK and Data pin output of I2C.

I understand below points from it. Let me correct or give your inputs.

1. In first Screen shot, Vector resistor value and Flag value indicate the interrupt for ACK after start I2C.

2. In second Screen shot, Vector resistor value and Flag value indicate the interrupt for I2C Tx.

3. In third Screen shot, Flag clears after serving interrupt.

4. In forth, Again stuck at LPM and at same time you can see the resistors value.

Please give your inputs.

Regards

Bhavdipsinh

Bhavdipsinh,

great to hear that you were able to solve it and also good that it's related to slave address and not the eUSCI or EEPROM itself.

So hope you increased your I2C experience by this exercise. Good luck for your project.

Best regards,
Dietmar