SLAZ149I October 2012 – May 2021 MSP430F168
TA Module
Functional
Interrupt is lost (slow ACLK)
Timer_A counter is running with slow clock (external TACLK or ACLK)compared to MCLK. The compare mode is selected for the capture/compare channel and the CCRx register is incremented by one with the occurring compare interrupt (if TAR = CCRx). Due to the fast MCLK the CCRx register increment (CCRx = CCRx+1) happens before the Timer_A counter has incremented again. Therefore the next compare interrupt should happen at once with the next Timer_A counter increment (if TAR = CCRx + 1). This interrupt gets lost.
Switch capture/compare mode to capture mode before the CCRx register increment. Switch back to compare mode afterwards.