8 SUPPLY VOLTAGE DETECTOR (SVD)
8-2
Seiko epson Corporation
S1C17F13 TeChniCal Manual
(Rev. 1.0)
Input Pin and External Connection
8.2
Input Pin
8.2.1
Table 8.2.1.1 shows the SVD input pin.
2.1.1 SVD Input Pin
Table 8.
Pin name
I/O
*
Initial status
*
Function
EXSVD
A
A (Hi-Z)
External power supply voltage detection pin
*
Indicates the status when the pin is configured for SVD.
If the port is shared with the EXSVD pin and other functions, the EXSVD function must be assigned to the port be-
fore SVD can be activated. For more information, refer to the “I/O Ports” chapter.
External Connection
8.2.2
SVD
External power
supply/regulator
etc.
SVD
analog block
EXSVD
2.2.1 Connection between EXSVD Pin and External Power Supply
Figure 8.
For the EXSVD pin input voltage range, refer to “Supply Voltage Detector Characteristics, EXSVD pin input volt-
age range V
EXSVD
” in the “Electrical Characteristics” chapter.
Clock Settings
8.3
SVD Operating Clock
8.3.1
When using SVD, the SVD operating clock CLK_SVD must be supplied to SVD from the clock generator.
The CLK_SVD supply should be controlled as in the procedure shown below.
1. Write 0x0096 to the MSCPROT.PROT[15:0] bits. (Remove system protection)
2. Enable the clock source in the clock generator if it is stopped (refer to “Clock Generator” in the “Power Supply,
Reset, and Clocks” chapter).
3. Set the following SVDCLK register bits:
- SVDCLK.CLKSRC[1:0] bits
(Clock source selection)
- SVDCLK.CLKDIV[2:0] bits
(Clock division ratio selection = Clock frequency setting)
4. Write a value other than 0x0096 to the MSCPROT.PROT[15:0] bits. (Set system protection)
The CLK_SVD frequency should be set to around 32 kHz.
Clock Supply in SLEEP Mode
8.3.2
When using SVD during SLEEP mode, the SVD operating clock CLK_SVD must be configured so that it will
keep supplying by writing 0 to the CLGOSC.
xxxx
SLPC bit for the CLK_SVD clock source.
If the CLGOSC.
xxxx
SLPC bit for the CLK_SVD clock source is 1, the CLK_SVD clock source is deactivated dur-
ing SLEEP mode and SVD stops with the register settings maintained at those before entering SLEEP mode. After
the CPU returns to normal mode, CLK_SVD is supplied and the SVD operation resumes.