MSP430x5xx MSP430x6xx Family User's Guide

　　The low-power modes LPM0 through LPM4 are configured with the CPUOFF， OSCOFF， SCG0， andSCG1 bits in the SR. The advantage of including the CPUOFF， OSCOFF， SCG0， and SCG1 mode-controlbits in the SR is that the present operating mode is saved onto the stack during an interrupt serviceroutine. Program flow returns to the previous operating mode if the saved SR value is not altered duringthe interrupt service routine. Program flow can be returned to a different operating mode by manipulatingthe saved SR value on the stack inside of the interrupt service routine. When setting any of themode-control bits， the selected operating mode takes effect immediately. Peripherals operating with anydisabled clock are disabled until the clock becomes active. Peripherals may also be disabled with their

　　individual control register settings. All I/O port pins and RAM/registers are unchanged. Wakeup from LPM0through LPM4 is possible through all enabled interrupts.When LPMx.5 （LPM3.5 or LPM4.5） is entered， the voltage regulator of the Power Management Module（PMM） is disabled. All RAM and register contents are lost. Although the I/O register contents are lost， theI/O pin states are locked upon LPMx.5 entry. See the Digital I/O chapter for further details. Wakeup fromLPM4.5 is possible via a power sequence， a RST event， or from specific I/O. Wakeup from LPM3.5 ispossible via a power sequence， a RST event， RTC event， or from specific I/