SLAZ162J October 2012 – May 2021 MSP430F2131
BCL Module
Functional
Erroneous ISR DCO DC generator enable
When MCLK and SMCLK are sourced from a clock other than the DCO, the SCG0 DCO control bit is erroneously cleared upon interrupt service routine entry from LPMx by the CPU. This enables the DCO DC generator causing additional current consumption. After executing the RETI instruction, the status register SCG0 bit will return to a set state turning off the DC generator, eliminating this added current. The increased current will only occur during the interrupt service routine, and is in the range of 20 uA at 3V.
Set SCG0 in software at the beginning of an interrupt service routine. This will reduce the time that the DC generator is enabled to four MCLK.