The MCU has one active mode and six software-selectable low-power modes of operation. An interrupt event can wake up the device from any of the low-power modes, service the request, and restore back to the low-power mode on return from the interrupt program.
Software can configure the following operating modes:
- Active mode (AM)
- Low-power mode 0 (LPM0)
- CPU is disabled
- ACLK and SMCLK remain active
- MCLK is disabled
- FLL loop control remains active
- Low-power mode 1 (LPM1)
- CPU is disabled
- FLL loop control is disabled
- ACLK and SMCLK remain active
- MCLK is disabled
- Low-power mode 2 (LPM2)
- CPU is disabled
- MCLK, FLL loop control, and DCOCLK are disabled
- DC generator of the DCO remains enabled
- ACLK remains active
- Low-power mode 3 (LPM3)
- CPU is disabled
- MCLK, FLL loop control, and DCOCLK are disabled
- DC generator of the DCO is disabled
- ACLK remains active
- Low-power mode 4 (LPM4)
- CPU is disabled
- ACLK is disabled
- MCLK, FLL loop control, and DCOCLK are disabled
- DC generator of the DCO is disabled
- Crystal oscillator is stopped
- Complete data retention
- Low-power mode 4.5 (LPM4.5)
- Internal regulator disabled
- No data retention
- Wake-up input from
RST/NMI, P1, and P2