UPD78F9500MA-CAC-A Datasheet, PDF (210/342 Pages) Renesas Technology Corp – 8-Bit Single-Chip Microcontrollers

CHAPTER 14 LOW-VOLTAGE DETECTOR
14.1 Functions of Low-Voltage Detector
The low-voltage detector (LVI) has following functions.
• Compares supply voltage (VDD) 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
VDD
VDD
N-ch
+
−
Reference
voltage source
4
LVIS3 LVIS2 LVIS1 LVIS0
Low-voltage detection
level select register (LVIS)
Internal bus
LVION LVIMD LVIF
Low-voltage detect
register (LVIM)
208
User’s Manual U18172EJ3V0UD
Internal reset signal
INTLVI