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M0A21/M0A23 Series
May 06, 2022
Page
105
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
V
DD
V
POR
Power-on Reset
2.2V
Figure 6.2-4 Power-on Reset (POR) Waveform
Low Voltage Reset (LVR)
If the Low Voltage Reset function is enabled by setting the Low Voltage Reset Enable Bit LVREN
(SYS_BODCTL[7]) to 1, after 200us delay, LVR detection circuit will be stable and the LVR function will
be active. Then LVR function will detect AV
DD
during system operation. When the AV
DD
voltage is lower
than V
LVR
and the state keeps longer than De-glitch time set by LVRDGSEL (SYS_BODCTL[14:12]),
chip will be reset. The LVR reset will control the chip in reset state until the AV
DD
voltage rises above
V
LVR
and the state keeps longer than De-glitch time set by LVRDGSEL (SYS_BODCTL[14:12]). The
default setting of Low Voltage Reset is enabled without De-glitch function. Figure 6.2-5 shows the Low
Voltage Reset waveform.
AV
DD
V
LVR
Low Voltage Reset
T
1
( < LVRDGSEL)
T
2
( =LVRDGSEL)
T
3
( =LVRDGSEL)
LVREN
200 us
Delay for LVR stable
Figure 6.2-5 Low Voltage Reset (LVR) Waveform
Brown-out Detector Reset (BOD Reset)
If the Brown-out Detector (BOD) function is enabled by setting the Brown-out Detector Enable Bit
BODEN (SYS_BODCTL[0]), Brown-out Detector function will detect AV
DD
during system operation.
When the AV
DD
voltage is lower than V
BOD
which is decided by BODEN and BODVL
(SYS_BODCTL[17:16]) and the state keeps longer than De-glitch time set by BODDGSEL