I am interfacing msp430 with rtc using i2c protocols.here is the program: WDTCTL = WDTPW + WDTHOLD; P1SEL |= BIT6 +BIT7; P1SEL2|= BIT6 +BIT7; UCB0CTL1 |= UCSWRST; UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;// I2C Master, synchronous mode UCB0CTL1 = UCSSEL_2 ; UCB0BR0 = 12; UCB0BR1 = 0; UCB0I2CSA = 0x34; UCB0CTL1 &= ~UCSWRST ; //everythingis fine upto here.scl is high here. UCB0CTL1 |= UCTR + UCTXSTT; /// here scl clock goes low. uctr=1 but uctxstt=0. any suggestions??