23.7.4 Sleep Mode Operation

During sleep modes, the ONDEMAND and RUNSTDBY bits in the Control A register (CTRLA) controls the behavior of the FREQM clock requests, in cases where the FREQM is enabled (CTRLA.ENABLE = 1) during a Sleep mode.

Table 23-1. FREQM Sleep Behavior
CTRLA.RUNSTDBY CTRLA.ONDEMAND CTRLA.ENABLE Description
X x 0 Disabled
0 0 1 Always request the clocks in all sleep modes, except in Standby mode.
0 1 1 On-demand clocks request in all sleep modes, except in Standby mode.
1 0 1 Always request the clocks in all sleep modes.
1 1 1 On-demand clocks request in all sleep modes.
Note: By default, if RUNSTDBY = 0, an ongoing measurement is stopped when the device is going to Standby Sleep mode. A new measurement will be restarted when the device exits the Standby Sleep mode.