7.7.2 PMU0CF: Power Management Unit Configuration
Bit
7
6
5
4
3
2
1
0
Name
SLEEP
SUSPEND
CLEAR
RSTWK
RTCFWK
RTCAWK
PMATWK
CPT0WK
Access
W
W
W
R
RW
RW
RW
RW
Reset
0
0
0
Varies
Varies
Varies
Varies
Varies
SFR Page = 0x0; SFR Address: 0xB5
Bit
Name
Reset
Access
Description
7
SLEEP
0
W
Sleep Mode Select.
Writing a 1 to this bit places the device in Sleep mode.
6
SUSPEND 0
W
Suspend Mode Select.
Writing a 1 to this bit places the device in Suspend mode.
5
CLEAR
0
W
Wake-up Flag Clear.
Writing a 1 to this bit clears all wake-up flags.
4
RSTWK
Varies
R
Reset Pin Wake-up Flag.
This bit is set to 1 if a glitch has been detected on RSTb.
3
RTCFWK
Varies
RW
RTC Oscillator Fail Wake-up Source Enable and Flag.
Read: Hardware sets this bit to 1 if the RTC oscillator failed.
Write: Write this bit to 1 to enable wake-up on an RTC oscillator failure.
2
RTCAWK
Varies
RW
RTC Alarm Wake-up Source Enable and Flag.
Read: Hardware sets this bit to 1 if the RTC Alarm occured.
Write: Write this bit to 1 to enable wake-up on an RTC Alarm.
1
PMATWK
Varies
RW
Port Match Wake-up Source Enable and Flag.
Read: Hardware sets this bit to 1 if Port Match event occured.
Write: Write this bit to 1 to enable wake-up on a Port Match event.
0
CPT0WK
Varies
RW
Comparator0 Wake-up Source Enable and Flag.
Read: Hardware sets this bit to 1 if a Comparator 0 rising edge caused the last wake-up.
Write: Write this bit to 1 to enable wake-up on a Comparator 0 rising edge.
Read-modify-write operations (ORL, ANL, etc.) should not be used on this register. Wake-up sources must be re-enabled each time
the SLEEP or SUSPEND bits are written to 1.
The Low Power Internal Oscillator cannot be disabled and the MCU cannot be placed in Suspend or Sleep Mode if any wake-up flags
are set to 1. Software should clear all wake-up sources after each reset and after each wake-up from Suspend or Sleep Modes.
PMU0 requires two system clocks to update the wake-up source flags after waking from Suspend mode. The wake-up source flags
will read 0 during the first two system clocks following the wake from Suspend mode.
EFM8SB2 Reference Manual
Power Management and Internal Regulators
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