23 SUPPLY VOLTAGE DETECTOR (SVD)
S1C17704 TECHNICAL MANUAL
EPSON
23-3
23.3 Controlling the SVD Operation
The SVD module starts operating to detect the supply voltage level by writing 1 to SVDEN (D0/SVD_EN register)
and stops when 0 is written to SVDEN.
∗
SVDEN
: SVD Enable Bit in the SVD Enable (SVD_EN) Register (D0/0x5100)
The detection results can be read from SVDDT (D0/SVD_RSLT register).
∗
SVDDT
: SVD Detection Result Bit in the SVD Detection Result (SVD_RSLT) Register (D0/0x5102)
The read value indicates the detection result as follows:
• SVDDT = 0 when supply voltage (V
DD
)
≥
compare voltage
• SVDDT = 1 when supply voltage (V
DD
) < compare voltage
Furthermore, if SVDEN is set to 1 when the SVD interrupt has been enabled, an interrupt will occur when the
supply voltage drops under the compare voltage and it sets the detection result to 1. By using this interrupt, the
application program can display for battery exhaustion or setting heavy load protection mode. See the subsequent
section for control of the interrupt.
When an interrupt occurs due to temporary voltage sags, it will not be canceled even if the voltage returns over the
compare voltage. Read SVDDT in the interrupt handler routine to check the current status.
Notes
: • After the SVD module starts operating, 500 µs (max.) is required until a stable detection
result can be read. When reading the detection results without using an interrupt, wait for the
stabilization time before reading SVDDT (D0/SVD_RSLT register) after writing 1 to SVDEN
(D0/SVD_EN register).
• The SVD operation increases current consumption. Therefore, set SVDEN to 0 to disable the
SVD operation if supply voltage detection is not necessary.
Summary of Contents for S1C17704
Page 1: ...TECHNICAL MANUAL S1C17704 CMOS 16 BIT SINGLE CHIP MICROCOMPUTER ...
Page 22: ...1 OVERVIEW 1 10 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 42: ...3 MEMORY MAP BUS CONTROL 3 12 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 82: ...6 INTERRUPT CONTROLLER ITC 6 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 108: ...8 CLOCK GENERATOR CLG 8 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 112: ...9 PRESCALER PSC 9 4 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 138: ...10 I O PORTS P 10 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 156: ...11 16 BIT TIMERS T16 11 18 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 208: ...14 8 BIT OSC1 TIMER T8OSC1 14 16 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 234: ...16 STOPWATCH TIMER SWT 16 14 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 242: ...17 WATCHDOG TIMER WDT 17 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 264: ...18 UART 18 22 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 300: ...20 I2C 20 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 320: ...21 REMOTE CONTROLLER REMC 21 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 360: ...24 ON CHIP DEBUGGER DBG 24 6 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 362: ...25 BASIC EXTERNAL WIRING DIAGRAM 25 2 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...