Datasheet

Section 26 Low-Voltage Detection Circuits
Page 856 of 982 REJ09B0465-0300 Rev. 3.00
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
26.1 Features
• Power-on reset function
Monitors the power-supply voltage input to the VCC pin to generate an internal reset signal
when power is first supplied.
Releases a reset when the power-supply voltage rises above the specified voltage.
• Low-voltage detection function
Reset function: Monitors the power-supply voltage, and generates an internal reset signal when
the voltage falls below a specified value.
Interrupt function: Monitors the power-supply voltage, and generates an interrupt when the
voltage falls below or rises above respective specified values.
Detection levels: Nine levels are available for LVD1 and two levels are available for LVD0.
(The level is fixed for LVD2.
External voltage input function: For detection, external pins can be selected for a detection
voltage and a reference voltage, respectively (LVD2 only).
Q
Vdet2
Vdet1
Vdet0
LVD0
LVD1
LVD2
VCC
R
S
LD2CRH
LD2CRL
LD1CRH
LD1CRL
LD0CRH
LD0CRL
Ladder
resistor
Interrupt
control circuit
Detection
voltage
generator
CK
Prescaler
R
Reset control
circuit
Control
circuit
Internal
reset signal
Interrupt
request
φloco
+
-
+
-
+
-
VDCPR
Figure 26.1 Block Diagram of Low-Voltage Detection Circuits