Filter
Top Products
130
CHAPTER 7 RESETS
■ Status of Reset Cause Bit and Low Voltage Detection Bit
Figure 7.5-3 Status of Reset Cause Bit and Low Voltage Detection Bit
*: The LVRF bit exist in the low voltage/CPU operation detection reset control register (LVRC).
(1) At power-on
Power-on reset bit (PONR) , ERST, and LVRF are set to "1" at power on.
(2) Bit clear
Bit is cleared by reading the WDTC register and by writing "0" to LVRF.
(3) At low voltage detection (4.0 V ± 0.3 V)
The LVRF and ERST bits are set to "1" at low voltage detection of V
CC
= 4.0 V ± 0.3 V.
(4) Bit clear
Bit is cleared by reading the WDTC register and by writing "0" to LVRF.
(1)
(2)
(3)
(4)
1
→
0
→
0
→
0
1
or
0
→
0
→
1
→
0
1
or
0
→
0
→
1
→
0
Vcc
Vcc=4V
Flag status
at power-on
Bit
clear
Flag status at
low voltage
detection (4V)
Bit
clear
PONR bit
(power-on)
ERST bit (external reset
input, CPU operation detection,
or LVRF = 1)
LVRF bit*
(low voltage detection
4V
±
0.3V)