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7.3 Function
Two detection voltages (VDxLVL, x=1-2) can be set in the voltage detection circuit. For each voltage, enabling/
disabling the voltage detection and the operation to be executed when the supply voltage (VDD) becomes lower than
the detection voltage (VDxLVL) can be programmed.
7.3.1
Enabling/disabling the voltage detection operation
Setting VDCR2<VDxEN> to "1" enables the voltage detection operation. Setting it to "0" disables the oper-
ation.
VDCR2<VDxEN> is cleared to "0" immediately after a power-on reset or a reset by an external reset input is
released.
Note:When the supply voltage (VDD) is lower than the detection voltage (VDxLVL), setting VDCR2<VDxEN>
to "1" generates a voltage detection interrupt request signal or a voltage detection reset signal at the
time.
7.3.2
Selecting the voltage detection operation mode
If the voltage detection operation mode is set to generate voltage detection interrupt request signals
(VDCR1<VDxMOD>="0") and VDCR2<VDxEN> is set to "1", a voltage detection interrupt request signal is
generated when the supply voltage (VDD) becomes lower than the detection voltage (VDxLVL).
If the voltage detection operation mode is set to generate voltage detection reset signals
(VDCR1<VDxMOD>="1") and VDCR2<VDxEN> is set to "1", a voltage detection reset signal is generated
when the supply voltage (VDD) becomes lower than the detection voltage (VDxLVL).
VDCR1 and VDCR2 are initialized by a power-on reset or an external reset input only. Therefore, the voltage
detection reset signals are generated continuously, as long as the supply voltage (VDD) is lower than the detection
voltage (VDxLVL).
Note:If the voltage detection mode is set to generate voltage detection interrupt request signals and the supply
voltage (VDD) becomes lower than the detection voltage (VDxLVL) in the STOP, IDLE0 or SLEEP0
mode, a voltage detection interrupt request signal is generated after the operation mode is released and
returned to NORMAL or SLOW mode.
Detection voltage level
VDD level
Voltage detection interrupt
request signal
VDCR2<VDxEN>
Voltage detection reset signal
Figure 7-2 Voltage Detection Interrupt Request Signal and Voltage Detection Reset Signal
7.3.3
Selecting the detection voltage level
Select a detection voltage at VDCR1<VDxLVL>.
TMP89FH46L
7. Voltage Detection Circuit
7.3 Function
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