11 SUPPLY VOLTAGE DETECTOR (SVD3)
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
11-1
(Rev. 2.00)
11 Supply Voltage Detector (SVD3)
11.1 Overview
SVD3 is a supply voltage detector to monitor the V
DD
voltage, or an external voltage detection input pin. The main
features are listed below.
• Power supply voltage to be detected: Selectable from V
DD
and external power sources (EXSVD0, EXSVD1)
• 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 11.1.1 shows the configuration of SVD3.
Table 11.1.1 SVD3 Configuration of S1C31D50/D51
Item
48-pin package
64-pin package
80-pin package
100-pin package
Power supply voltage to be detected
V
DD
and two externally input voltages (EXSVD0, EXSVD1)
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 CPU core
SVDMD[1:0]
Sampling timing
generator
Voltage
comparator
circuit
Interrupt/reset
control circuit
Detection
result counter
External voltage
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
EXSVD0
EXSVD1
Inter
nal data
bu
s
Figure 11.1.1 SVD3 Configuration