Hi
I am trying to implement i2c data transmission in interrupt mode for msp430f6438 data is transmission is happen but when i want to see data in logic analyzer its not showing and always i2c scl pin is low even slave device having pull up 2k and code shown below and my slave device is operating with 100khz.please help me
void I2CMaster_Init();
unsigned char *PTxData; // Pointer to TX data
unsigned char TXByteCtr;
unsigned char RXData;
unsigned char RXCompare;
unsigned char TxData[] = // Table of data to transmit
{
0x00
};
int main(void)
{
uint32_t initstatus = I2C_Success;
unsigned int i,j;
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog
I2CMaster_Init();
PTxData = TxData; // TX array start address
// Place breakpoint here to see each
// transmit operation.
// TXByteCtr = sizeof(TxData); // Load TX byte counter
UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition
while (1)
{
PTxData = TxData; // TX array start address
// Place breakpoint here to see each
// transmit operation.
TXByteCtr = sizeof(TxData); // Load TX byte counter
__bis_SR_register(GIE); // Enter LPM0, enable interrupts
}
return 0;
}
void I2CMaster_Init()
{
unsigned int i;
P2SEL |= 0x06; // Assign I2C pins to USCI_B0
//P2DIR &= ~0x06;
P2REN |= 0x04;
P2OUT |= 0x04;
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode
UCB0CTL1 |= UCSSEL_2; // Use SMCLK, keep SW reset
UCB0BR0 = 10; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0I2CSA = 0x18; // Slave Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
condition
UCB0IE |= UCTXIE + UCRXIE; // Enable TX interrupt
//for(i=0;i<50;i++);
}
// USCI_B0 Data ISR
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
{
unsigned int j;
switch(__even_in_range(UCB0IV,12))
{
case 0: break; // Vector 0: No interrupts
case 2: break; // Vector 2: ALIFG
case 4: break; // Vector 4: NACKIFG
case 6: break; // Vector 6: STTIFG
case 8: break; // Vector 8: STPIFG
case 10: // Vector 10: RXIFG
RXData = UCB0RXBUF; // Get RX data
printf("hai");
UCB0CTL1 |= UCTXSTP; // I2C start condition
break;
case 12: // Vector 12: TXIFG
while(TXByteCtr) // Delay required between transaction
{
UCB0TXBUF = *PTxData++; // Load TX buffer
TXByteCtr--;
}
UCB0IFG &= ~UCTXIFG; // Clear USCI_B0 TX int flag
// UCB0CTL1 &= ~UCTR ; // I2C recivecondition
default: break;
}
}
Thanks in advance
