I am using a MSP430F6721 for the first time and having problems with the UART (A0). I am using a 32KHz crystal on XT1. I look at the clock on PJ.3 and it is at 32KHz. I use ACLK for the baudrate clock and have a baudrate of 9600. I set UCA0BR0 to 0x3. I try and transmit a byte and find that the bit width is 92uS rather than 104uS. I find I cannot write to the MCTL register. It is always 0x0000. According to the user guide the UCBRF is all zeros and UCBRSx is 0x3. I am using IAR assembler. In the user guide it says there are 3 bits for UCBRSx. In the Assembler it shows a register named UCA0MCTLW and UCBRSx has 8 bits. (plus 4 for UCBRFx and UCOS16). I am modifying all registers while UCWRST =1. It seems, to me, that the user guide does not match the IAR program. I have not had problems with other MCUs I have used which are similar.
Any thoughts as to what I am doing wrong?
Thanks
Peter