HD64F3687HV Datasheet, PDF (398/538 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

Section 20 Power-On Reset and Low-Voltage Detection Circuits (Optional)
Table 20.1 LVDCR Settings and Select Functions
LVDCR Settings
LVDE LVDSEL LVDRE LVDDE
0
*
*
*
1
1
1
0
1
0
0
1
1
0
0
1
1
0
1
1
Legend: *: means invalid.
LVDUE
*
0
0
1
1
Power-On
Reset
O
O
O
O
O
Select Functions
LVDR
Low-Voltage- Low-Voltage-
Detection Detection
Falling
Rising
Interrupt
Interrupt



O



O


O
O
O
O
O
20.2.2 Low-Voltage-Detection Status Register (LVDSR)
LVDSR indicates whether the power-supply voltage falls below or rises above the respective
specified values.
Initial
Bit
Bit Name Value R/W
7 to 2 
All 1

1
LVDDF 0*
R/W
0
LVDUF 0*
R/W
Note: * Initialized by LVDR.
Description
Reserved
These bits are always read as 1, and cannot be modified.
LVD Power-Supply Voltage Fall Flag
[Setting condition]
When the power-supply voltage falls below Vint (D) (typ.
= 3.7 V)
[Clearing condition]
Writing 0 to this bit after reading it as 1
LVD Power-Supply Voltage Rise Flag
[Setting condition]
When the power supply voltage falls below Vint (D) while
the LVDUE bit in LVDCR is set to 1, then rises above Vint
(U) (typ. = 4.0 V) before falling below Vreset1 (typ. = 2.3
V)
[Clearing condition]
Writing 0 to this bit after reading it as 1
Rev.5.00 Nov. 02, 2005 Page 364 of 500
REJ09B0027-0500