tmp89cm42 TOSHIBA Semiconductor CORPORATION, tmp89cm42 Datasheet - Page 95

• Manufacturer Part Number: tmp89cm42
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

RB000
7. Voltage Detection Circuit
7.1
VDD
signals and voltage detection reset signals.
circuit, a comparator and control registers.
detection voltage selection circuit selects a voltage according to the specified detection voltage (VDxLVL) (x = 1 or
2), and the comparator compares it with the reference voltage. When the comparator detects the selected voltage, a
voltage detection reset signal or an INTVLTD interrupt request signal can be generated.
by software. In the former case, a voltage detection reset signal is generated when the supply voltage (VDD) becomes
lower than the detection voltage (VDxLVL). In the latter case, an INTVLTD interrupt request signal is generated when
the supply voltage (VDD) falls to the detection voltage level.
Configuration
The voltage detection circuit detects any decrease in the supply voltage and generates INTVLTD interrupt request
The voltage detection circuit consists of a reference voltage generation circuit, a detection voltage level selection
The supply voltage (VDD) is divided by the ladder resistor and input to the detection voltage selection circuit. The
Whether to generate a voltage detection reset signal or an INTVLTD interrupt request signal can be programmed
Note:The voltage detection circuit may operate improperly, depending on fluctuations in the supply voltage (VDD).
Note:Since the comparators used for voltage detection do not have a hysteresis structure, INTVLTD interrupt request
Refer to the electrical characteristics and take them into consideration when designing equipment.
signals may be generated frequently if the supply voltage (VDD) is close to the detection voltage (VDxLVL).
INTVLTD interrupt request signals may be generated not only when the supply voltage falls to the detection
voltage but also when it rises to the detection voltage.
VDCR1
Reference voltage
generation circuit
Figure 7-1 Voltage Detection Circuit
−
+
−
+
Internal bus
VDCR2
Page 81
F/F
F/F
signal generation
Interrupt request
circuit
Voltage detection reset signal 1
INTVLTD interrupt request signal
Voltage detection reset signal 2
TMP89CM42