I am using a MSP430G2553 and communicate with it to a PC using the UART interface. The baud rate is 9600. For accuracy reasons (sic) I selected ACLK clocked by an external 32.768kHz crystal to provide the clock for the UART module. Well, it worked until recently the PC was not recognizing the sent characters. A bit of research showed that the baud rate error in that configuration is quite significant (20%).
Now the idea was to use a higher frequency to clock the UART in order to minimize the baud rate error. Well, I was all the time under the assumption that the DCO can use the external crystal together with a PLL to generate a higher frequency.
After reading through the data sheet it seems that it is not the case! DCO is relying in an inaccurate RC element rather than to use the low frequency crystal.
Now, having these 2 options, what is the best to do? Will be DCO at e.g. 16MHz with an inaccurate RC as a source provide better baud rate error than the 32kHz crystal?