SLAZ224P October 2012 – May 2021 MSP430F46191
USCI Module
Functional
UART/IrDA Mode Lost Characters
When configured for UART/IrDA mode, the USCI baud rate generator may halt operation under the following conditions:
1 - IrDA mode: repeated invalid start bits on the receive line
or
2 - UART/IrDA modes: positive pulse on the receive line during break character reception inside the stop bit time slot (the second stop bit time slot in case of UCSPB=1) with a pulse width that passes the deglitch filter but is shorter than half a bit time.
After halting, additional characters will be ignored. Transmit functionality is not affected.
Check the UCBUSY flag status periodically in software. If the flag is set and no character has been received in the expected time, reset the USCI module in software. To reset the USCI module, toggle UCSWRST and re-enable the USCI interrupts.