__bis_SR_register_on_exit sets the bits specified in mask in the saved status register of an interrupt function (i.e. it bitwise ands the complement of mask into the saved status register). This allows you to change the operating mode of the MSP430 on return from the interrupt service routine, such as changing the low power mode.
__bis_SR_register_on_exit returns the value of the saved MSP430 status register before the update.
__bis_SR_register_on_exit is an intrinsic function and produces inline code.
__bis_SR_register_on_exit can only be used in interrupt functions—an error is reported if it is used outside an interrupt function.