CHAPTER 14 LOW-VOLTAGE DETECTOR
User’s Manual U18172EJ2V0UD
207
Figure 14-6. Example of Software Processing After Release of Reset (1/2)
•
If supply voltage fluctuation is 50 ms or less in vicinity of LVI detection voltage
;
The detection level is set with LVIS.
Yes
No
Setting LVI
Detection voltage or more
(
LVIF = 0
?)
Yes
LVIF = 0
Restarting the timaer H1
(
TMHE1 = 0
TMHE1 = 1
)
No
;
Clear low-voltage detection flag.
;
Clear timaer counter and timer starts.
LVI reset
; Check reset source
Note
Initialization of ports
Setting WDT
Reset
Initialization
processing <1>
Setting 8-bit timer H1
(50 ms
is measured)
Source
:
f
RL
(
2.1 MHz
(
MAX.
)) /
2
12
,
51 ms when the compare value is
25
Timer starts
(
TMHE1 = 1
)
;
f
XP
=
High-speed internal oscillation clock
(
8.4 MHz
(
MAX.
))
/2
2
(default value)
Clears WDT
50 ms has passed?
(TMIFH1 = 1?)
Initialization
processing <2>
; S
pecify the division ratio of the system clock,
setting Timaer, setting
A/D Converter, etc.
The low-voltage detector is operated (LVION = 1)
Note
A flowchart is shown on the next page.