SLAZ290AC October 2012 – May 2021 MSP430F5438A , MSP430F5438A-EP
USCI Module
Functional
Framing Error after USCI SW Reset (UCSWRST)
While receiving a byte over USCI-UART (with UCBUSY bit set), if the application resets the USCI module (software reset via UCSWRST), then a framing error is reported for the next receiving byte.
1. If possible, do not reset USCI-UART during an ongoing receive operation; that is, when UCBUSY bit is set.
2. If the application software resets the USCI module (via the UCSWRST bit) during an ongoing receive operation, then set and reset the UCSYNC bit before releasing the software USCI reset.
Workaround code sequence:
bis #UCSWRST, &UCAxCTL1 ; USCI SW reset
;Workaround begins
bis #UCSYNC, &UCAxCTL0 ; set synchronous mode
bic #UCSYNC, &UCAxCTL0 ; reset synchronous mode
;Workaround ends
bic #UCSWRST, &UCAxCTL1 ; release USCI reset