Hello,
I am facing a peculiar problem using MSP430F5437. All my questions are related to serial comm.
1) I am using a baud rate of 9600, sourced from smclk, which i believe is 1.04 MHZ. I always have to use ucos=1 to get this baud. If I try generating this baud wihtout oversampling, My device cannot communicate. Below is the code I am using to set the baud. Is there a way I can get 9600 without using oversampling?
UCA0CTL1 |= 0x01;
UCA0CTL0 |= UCMODE1; // Address bit transmission
UCA0CTL0 |= UC7BIT; // 7 bit data
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 6;
UCA0BR1 = 0;
UCA0MCTL = UCBRS_0 + UCBRF_13 + UCOS16;
UCA0CTL1 |= UCDORM ; // Message with address byte will generate int
UCA0CTL1 &= ~UCSWRST; // RESET USCI state machine
UCA0IE |= UCRXIE; // Enable USCI_A0 RX

2) I am using a RS-485 convertor. When I transmit a byte, i enable listen on the serial port. this result an Rx interrupt when the byte is tx on the line. In the interrupt I drive the rs-485 line low so that MSP430 switches back to rx mode. After some period of running, I get framing error in the byte that was tx by the MSP430. I dont get framing errors on received data. As a result my MSP430 gets stuck in transmit mode. I have a timer which start counting when I put a byte in txbuffer, and stops when I listen the byte in the rx interrupt. In case of framing error, rx interrupt never occurs, so the timer times out. In the debugger I see the txinterrupt bit set, but I am unable to figure out a way to clear it.

I hope some1 can point me in the right direction.

thanks
Muk

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