10 SUPPLY VOLTAGE DETECTOR (SVD3)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
10-1
TECHNICAL MANUAL (Rev. 1.0)
10 Supply Voltage Detector (SVD3)
10.1 Overview
SVD3 is a supply voltage detector to monitor the power supply voltage on the V
DD
pin or the voltage applied to an
external pin. The main features are listed below.
• Power supply voltage to be detected: Selectable from V
DD
and external power sources (EXSVD0 and EXSVD1)
(Note: See the table below.)
• Detectable voltage level:
Selectable from among 32 levels (max.)
(Note: See the table below.)
• Detection results:
- Can be read whether the power supply voltage is lower than the detection
voltage level or not.
- Can generate an interrupt or a reset when low power supply voltage is de-
tected.
• Interrupt:
1 system (Low power supply voltage detection interrupt)
• Supports intermittent operations:
- Three detection cycles are selectable.
- Low power supply voltage detection count function to generate an inter-
rupt/reset when low power supply voltage is successively detected the
number of times specified.
- Continuous operation is also possible.
Figure 10.1.1 shows the configuration of SVD3.
Table 10.1.1 SVD3 Configuration of S1C17M20/M21/M22/M23/M24/M25
Item
S1C17M20/M23
S1C17M21/M24
S1C17M22/M25
24-pin package
32-pin package
Power supply voltage to be detected
V
DD
and one externally input voltage (EXSVD0)
Detectable voltage level
V
DD
: 28 levels (1.8 to 5.0 V)/external voltage: 32 levels (1.2 to 5.0 V)
SVD3
To system reset circuit
To interrupt controller
SVDMD[1:0]
Sampling timing
generator
Voltage
comparator
circuit
Interrupt/reset
control circuit
Detection
result counter
EXSVD0/1
selector
MODEN
SVDC[4:0]
VDSEL
EXSEL
SVDSC[1:0]
SVDIE
SVDIF
SVDDT
SVDRE[3:0]
CLKSRC[1:0]
CLKDIV[2:0]
Clock generator
DBRUN
CLK_SVD3
V
DD
EXSVD1
EXSVD0
Inter
nal data
bu
s
(
)
Figure 10.1.1 SVD3 Configuration