8.3.3 Power-On Reset (POR)
The POR ensures that the EFM32 Jade Gecko does not start up before the supply voltage V
DD
has reached the threshold voltage
VPORthr (see Device Datasheet Electrical Characteristics for details). Before the threshold voltage is reached, the EFM32 Jade Gecko
is kept in reset state. The operation of the POR is illustrated in
Figure 8.2 RMU Power-on Reset Operation on page 145
, with the active
low POWERONn reset signal. The reason for the “unknown” region is that the corresponding supply voltage is too low for any reliable
operation.
POWERONn
V
DD
time
V
Unknown
VPORthr
Figure 8.2. RMU Power-on Reset Operation
8.3.4 Brown-Out Detector (BOD)
The EFM32 Jade Gecko The BODs also include hysteresis, which prevents instability in the corresponding BROWNOUTn line when
the supply is crossing the VBODthr limit or the AVDD bods drops below decouple pin (DEC). The operation of the BOD is illustrated in
Figure 8.3 RMU Brown-out Detector Operation on page 145
. The “unknown” regions are handled by the POR module.
Unknown
BROWNOUTn
V
DD
time
V
Unknown
VBODthr
VBODhyst
VBODhyst
Figure 8.3. RMU Brown-out Detector Operation
EFM32JG1 Reference Manual
RMU - Reset Management Unit
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