Fujitsu FR81S User Manual
CHAPTER 32: LOW-VOLTAGE DETECTION (EXTERNAL
LOW-VOLTAGE DETECTION)
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : LOW-VOLTAGE DETECTION (EXTERNAL LOW-VOLTAGE DETECTION)
FUJITSU SEMICONDUCTOR CONFIDENTIAL
9
LVD5F_SEL[3:0]
External power supply fall detection voltage setting
0110
3.90V ±8%
0111
4.00V ±8%
1000
4.10V ±8%
1001
4.20V ±8%
1010
4.30V ±8%
others
Setting prohibited
* LVD5F_SEL[3:0] bits can be rewritten only when LVD5F_OE = "1".
[bit3] LVD5F_OE (Low Voltage Detect external 5v Fall Output Enable): External power-supply fall
detection output enable setting
This bit is the output enable signal for external voltage fall detection.
LVD5F_OE
External power supply fall detection output enable setting
0
Enable
1
Stop
* This bit is initialized by only power-on reset.
[bit1] LVD5F_RI (Low Voltage Detect external 5v Fall Reset Interrupt select):
This bit selects either low-voltage detection reset or interrupt.
LVD5F_RI
Low-voltage detection reset / Interrupt selection setting
0
Reset
1
Interrupt
[bit0] LVD5F_F (Low Voltage Detect external 5v Fall Flag): External fall detection flag
This flag shows is an external voltage fall detection flag.
LVD5F_F
External power supply fall detection flag
Read
Write
0
Not detected
Clear the flag
1
Detected
No effect on operation
If a fall in external voltage is detected, the LVD5F_F bit is set to "1".
This bit is cleared when a external reset is input.
MB91520 Series
MN705-00010-1v0-E
1160