
22 SUPPLY VOLTAGE DETECTOR (SVD)
S1C17705 TECHNICAL MANUAL
Seiko Epson Corporation
22-3
To use this interrupt, set SVDIE/SVD_IMSK register to 1. When SVDIE is set to 0 (default), interrupt requests
for this cause will not be sent to the interrupt controller (ITC).
If SVDIF is set to 1 while SVDIE is set to 1 (interrupt enabled), the SVD module outputs an interrupt request to
the ITC. An interrupt is generated if the ITC and S1C17 Core interrupt conditions are satisfied.
For more information on interrupt processing, see the “Interrupt Controller (ITC)” chapter.
Notes: To prevent interrupt recurrences, the SVD module interrupt flag SVDIF must be reset in the
interrupt handler routine after an SVD interrupt has occurred.
To prevent unwanted interrupts, SVDIF should be reset before enabling SVD interrupts with
SVDIE.
Control Register Details
22.6
6.1 List of SVD Registers
Table 22.
Address
Register name
Function
0x5066
SVD_CLK
SVD Clock Control Register
Selects the operating clock.
0x5100
SVD_EN
SVD Enable Register
Enables/disables the SVD operation.
0x5101
SVD_CMP
SVD Comparison Voltage Register
Sets the comparison voltage.
0x5102
SVD_RSLT
SVD Detection Result Register
Voltage detection results
0x5103
SVD_IMSK
SVD Interrupt Mask Register
Enables/disables interrupts.
0x5104
SVD_IFLG
SVD Interrupt Flag Register
Indicates/resets interrupt occurrence status.
The SVD module registers are described in detail below. These are 8-bit registers.
Note: When data is written to the registers, the “Reserved” bits must always be written as 0 and not 1.
SVD Clock Control Register (SVD_CLK)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
SVD Clock
Control Register
(SVD_CLK)
0x5066
(8 bits)
D7–4 –
reserved
–
0 when being read.
D3–2 CLKSRC
[1:0]
SVD clock source select
CLKSRC[1:0]
Clock source
0x1 R/W
0x3
0x2
0x1
0x0
reserved
OSC3/512
OSC1
IOSC/128
D1
–
reserved
–
0 when being read.
D0
CLKEN
SVD clock enable
1 Enable
0 Disable
0
R/W
D[7:4]
Reserved
D[3:2]
CLKSRC[1:0]: SVD Clock Source Select Bits
Select the clock source for the SVD circuit.
6.2 SVD Clock Source Selection
Table 22.
CLKSRC[1:0]
Clock source
0x3
Reserved
0x2
OSC3/512
0x1
OSC1
0x0
IOSC/128
(Default: 0x1)
When OSC1 is selected as the clock source, the OSC1 clock (typ. 32.768 kHz) is directly used as SVD-
CLK. When IOSC is selected as the clock source, SVDCLK is generated by dividing the IOSC clock
by 128. When OSC3 is selected as the clock source, SVDCLK is generated by dividing the OSC3 clock
by 512.
D1
Reserved