SLAA380B December 2007 – September 2018 MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619
The MSP430F261x features a range of upgraded peripherals compared to the MSP430F16x, such as the BCS+ and the Comparator+. This added functionality is partially achieved through the use of bits that were previously marked as reserved on the corresponding MSP430F1xx peripheral. Newer generation MSP430s such as the MSP430F261x make use of these bits to implement additional functionality. If left in the default state, the peripheral usually behaves identical to its MSP430F1xx counterpart. However, care must be taken not to unintentionally switch some of these bits, which can be caused by migrated MSP430F16x firmware. For example, consider the following comparison of CACTL2 control register of Comparator_A and Comparator_A+:
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Unused | P2CA1 | P2CA0 | CAF | CAOUT | |||
rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | r-(0) |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
CASHORT | P2CA4 | P2CA3 | P2CA2 | P2CA1 | P2CA0 | CAF | CAOUT |
rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | rw-(0) | r-(0) |
When firmware that uses the comparator module sets bit 7 and runs fine on an MSP430F16x is executed on an MSP430F261x device, it results in the comparator inputs being shorted together internally.