4 POWER SUPPLY
S1C17704 TECHNICAL MANUAL
EPSON
4-5
4.4 Heavy Load Protection Function
In order to ensure a stable circuit behavior and LCD display quality even if the power supply voltage fluctuates due
to driving an external load, the internal logic voltage regulator and the LCD system voltage regulator have a heavy
load protection function.
The internal logic voltage regulator enters heavy load protection mode by writing 1 to the HVLD bit (D4/VD1_CTL
register) and it ensures stable V
D1
output. Use the heavy load protection function when a heavy load such as a lamp
or buzzer is driven with a port output.
∗
HVLD
: V
D1
Heavy Load Protection Mode Bit in the V
D1
Control (VD1_CTL) Register (D4/0x5120)
The LCD system voltage regulator enters heavy load protection mode by writing 1 to the LHVLD bit (D4/
LCD_VREG register) and it ensures stable V
C1
–V
C5
outputs. Use the heavy load protection function when the LCD
display has inconsistencies in density.
∗
LHVLD
: LCD Heavy Load Protection Mode Bit in the LCD Voltage Regulator Control (LCD_VREG) Register
(D4/0x50a3)
Note
: Current consumption increases in heavy load protection mode, therefore do not set heavy load
protection mode with software if unnecessary.
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 ...