Datasheet

78K0/Kx2-L CHAPTER 22 LOW-VOLTAGE DETECTOR
R01UH0028EJ0400 Rev.4.00 672
Sep 27, 2010
22.2 Configuration of Low-Voltage Detector
The block diagram of the low-voltage detector is shown in Figure 22-1.
Figure 22-1. Block Diagram of Low-Voltage Detector
LVIS1 LVIS0
LVION
−
+
Reference
voltage
source
Internal bus
N-ch
Low-voltage detection level
selection register (LVIS)
Low-voltage detection register
(LVIM)
LVIS2 LVIS3
LVIF
INTLVI
Internal reset signal
4
LVISEL
EXLVI/P120/
INTP0
LVIMD
Low-voltage detection
level selector
Selector
Selector
VDD
VDD
Remark EXLVI/P120/INTP0 is mounted only on 78K0/KB2-L and 78K0/KC2-L.
22.3 Registers Controlling Low-Voltage Detector
The low-voltage detector is controlled by the following registers.
• Low-voltage detection register (LVIM)
• Low-voltage detection level select register (LVIS)
• Port mode register 12 (PM12)
(1) Low-voltage detection register (LVIM)
This register sets low-voltage detection and the operation mode.
This register can be set by a 1-bit or 8-bit memory manipulation instruction.
The generation of a reset signal other than an LVI reset clears this register to 00H.