Datasheet

User’s Manual U18172EJ3V0UD
208
CHAPTER 14 LOW-VOLTAGE DETECTOR
14.1 Functions of Low-Voltage Detector
The low-voltage detector (LVI) has following functions.
Compares supply voltage (V
DD) and detection voltage (VLVI), and generates an internal interrupt signal or
internal reset signal when VDD < VLVI.
Detection levels (ten levels) of supply voltage can be changed by software.
Interrupt or reset function can be selected by software.
Operable in STOP mode.
When the low-voltage detector is used to reset, bit 0 (LVIRF) of the reset control flag register (RESF) is set to 1 if
reset occurs. For details of RESF, refer to CHAPTER 12 RESET FUNCTION.
14.2 Configuration of Low-Voltage Detector
The block diagram of the low-voltage detector is shown in Figure 14-1.
Figure 14-1. Block Diagram of Low-Voltage Detector
LVION
Reference
voltage source
V
DD
N-ch
Low-voltage detection
level select register (LVIS)
Low-voltage detect
register (LVIM)
LVIS2
LVIMD
LVIF
INTLVI
Internal reset signal
4
V
DD
LVIS1 LVIS0
LVIS3
Low-voltage detection level selector
Selector
Internal bus
+