Datasheet

MSP430L092

MSP430C09x

www.ti.com

SLAS673 –SEPTEMBER 2010

Operating Modes

The MSP430 has one active mode and five software-selectable low-power modes of operation. An interrupt

event can wake up the device from any of the five low-power modes, service the request, and restore back to the

low-power mode on return from the interrupt program.

The following six operating modes can be configured by software:

• Active mode (AM)

– All clocks are active

• Low-power mode 0 (LPM0)

– CPU is disabled

– ACLK and SMCLK remain active for all sources

– MCLK is disabled

• Low-power mode 1 (LPM1)

– CPU is disabled

– ACLK and SMCLK remain active (for LF oscillator and CLKIN as source, HF oscillator is mapped to LF

oscillator as source)

– MCLK is disabled

• Low-power mode 2 (LPM2)

– CPU is disabled

– MCLK is disabled

– SMCLK is disabled

– ACLK remains active for all sources

• Low-power mode 3 (LPM3)

– CPU is disabled

– MCLK is disabled

– SMCLK is disabled

– ACLK remains active (for LF oscillator and CLKIN as source, HF oscillator is mapped to LF oscillator as

source)

• Low-power mode 4 (LPM4)

– CPU is disabled

– MCLK is disabled

– SMCLK is disabled

– ACLK is disabled

– Oscillators are stopped

LPM2 vs LPM3

If only MCLK is feed by the HF oscillator (SELA ≠ 00, SELS ≠ 00, SELM = 00 of CCSCTL4 register) the following

behavior is implemented:

• Entering LPM2 turns off the HF oscillator and starts again with the HF oscillator selected for MCLK

• Entering LPM3 turns off the HF oscillator and starts again with the LF oscillator selected for MCLK

The only difference between LPM2 and LPM3 is the selection of the source for MCLK when re-entering active

mode and, therefore, and the level of power savings.