SLAA419C October 2009 – April 2019 MSP430F5418 , MSP430F5418A , MSP430F5419 , MSP430F5419A , MSP430F5435 , MSP430F5435A , MSP430F5436 , MSP430F5436A , MSP430F5437 , MSP430F5437A , MSP430F5438 , MSP430F5438A
The logic for the Unified Clock System (UCS) has changed slightly for A revisions of silicon. The changes generally affect the conditions under which the four available reference oscillators, the reference oscillator (REFO), the very low frequency oscillator (VLO), and the two crystal oscillators (XT1 and XT2) are enabled or disabled. These differences are outlined extensively in the UCS chapter of the MSP430F5xx and MSP430F6xx Family User's Guide and should be reviewed for possible optimizations to the UCS configuration and overall power consumption. Existing UCS code should require no modification for proper execution.