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R01UH0336EJ0102 Rev.1.02
Page 305 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 8 Reset Controller
8.4.4
Details of POF / LVI Control Registers
(1)
POF - Power-on Flag Register
This register is used to confirm the state of the power-supply voltage for the
internal regulator (VDD).
When the voltage has fallen below the detection voltage, the POF bit is set to 1
(i.e. initialized).
Access
This register can be read in 8-bit units.
Address
FFFF FC00
H
Initial value
01
H
(2)
POFC - Power-on Flag Clear Register
This register is used to clear the POF bit in the POF register to 0.
Access
This register can be written in 8-bit units.
When read, the value returned is 00
H
.
Address
FFFF FC04
H
Initial value
00
H
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
POF
R
R
R
R
R
R
R
R
Table 8-11
POF Register Contents
Bit Position
Bit Name
Function
0
POF
This bit indicates the state of detection for the power-on flag.
0: Voltage VDD is above the detection voltage.
1: Voltage VDD is below the detection voltage (a low voltage from the power-
supply for the internal regulator has been detected).
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
POFC
R
R
R
R
R
R
R
W
Table 8-12
POFC Register Contents
Bit Position
Bit Name
Function
0
POFC
This bit controls clearing of the power-on flag register (the POF.POF bit).
Writing 1 to the POFC bit causes clearing of the POF bit to 0.
0: No effect
1: The POF bit is cleared to 0.