10 SUPPLY VOLTAGE DETECTOR (SVD3)
10-6
Seiko Epson Corporation
S1C17M20/M21/M22/M23/M24/M25
TECHNICAL MANUAL (Rev. 1.0)
Table 10.6.1 Clock Source and Division Ratio Settings
SVDCLK.
CLKDIV[2:0] bits
SVDCLK.CLKSRC[1:0] bits
0x0
0x1
0x2
0x3
IOSC
OSC1
OSC3
EXOSC
0x7, 0x6
Reserved
1/1
Reserved
1/1
0x5
1/512
1/512
0x4
1/256
1/256
0x3
1/128
1/128
0x2
1/64
1/64
0x1
1/32
1/32
0x0
1/16
1/16
(Note) The oscillation circuits/external input that are not supported in this IC cannot be
selected as the clock source.
Note
: The clock frequency should be set to around 32 kHz.
SVD3 Control Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
SVDCTL
15 VDSEL
0
H1
R/WP –
14–13 SVDSC[1:0]
0x0
H0
R/WP Writing takes effect when the SVDCTL.
SVDMD[1:0] bits are not 0x0.
12–8 SVDC[4:0]
0x1e
H1
R/WP –
7–4 SVDRE[3:0]
0x0
H1
R/WP
3
EXSEL
0
H1
R/WP
2–1 SVDMD[1:0]
0x0
H0
R/WP
0
MODEN
0
H1
R/WP
Bit 15
VDSEL
This bit selects the power supply voltage to be detected by SVD3.
1 (R/WP): Voltage applied to the EXSVD0/1 pin
0 (R/WP): V
DD
Bits 14–13 SVDSC[1:0]
These bits set the condition to generate an interrupt/reset (number of successive low voltage detec-
tions) in intermittent operation mode (SVDCTL.SVDMD[1:0] bits = 0x1 to 0x3).
Table 10.6.2 Interrupt/Reset Generating Condition in Intermittent Operation Mode
SVDCTL.SVDSC[1:0] bits
Interrupt/reset generating condition
0x3
Low power supply voltage is successively detected eight times.
0x2
Low power supply voltage is successively detected four times.
0x1
Low power supply voltage is successively detected twice.
0x0
Low power supply voltage is successively detected once.
This setting is ineffective in continuous operation mode (SVDCTL.SVDMD[1:0] bits = 0x0).
Bits 12–8 SVDC[4:0]
These bits select an SVD detection voltage V
SVD
/EXSVD detection voltage V
SVD_EXT
for detecting
low voltage.
Table 10.6.3 Setting of SVD Detection Voltage V
SVD
/EXSVD Detection Voltage V
SVD_EXT
SVDCTL.SVDC[4:0] bits
SVD detection voltage V
SVD
/
EXSVD detection voltage V
SVD_EXT
[V]
0x1f
High
0x1e
↑
0x1d
:
0x02
0x01
↓
0x00
Low
For the configurable range and voltage values, refer to “Supply Voltage Detector Characteristics, SVD
detection voltage V
SVD
/EXSVD detection voltage V
SVD_EXT
” in the “Electrical Characteristics” chapter.