3.11.4 Voltage Monitor (Low Battery Indicator)

A programmable voltage monitor is provided for low battery indication. If the supply voltage falls below the selected threshold, a flag is set in the voltage monitor control and status register (VMCSR.VMF) and an interrupt is issued if masked in VMCSR.VMIM.

The comparator for the voltage monitor has fifteen internally programmable thresholds that are selected by the VMCSR.VMLS bits. The VMF bit indicates if the supervised voltage is below or above this. Setting the VMCSR.VMLS[3:0] bits to ‘0’ disables the voltage monitor.

The voltage monitor must be activated in the corresponding PRR0.PRVM power reduction register (see Sleep Modes and Active Power Reduction). The voltage monitor is only used in 3V applications.

For more information about the voltage monitor register, see Power Management Register Description .