22 LCD DRIVER (LCD)
S1C17704 TECHNICAL MANUAL
EPSON
22-9
22.6 Display Control
22.6.1 Turning Display On and Off
The LCD display status can be controlled using DSPC[1:0] (D[1:0]/LCD_DCTL register).
∗
DSPC[1:0]
: LCD Display Control Bits in the LCD Display Control (LCD_DCTL) Register (D[1:0]/0x50a0)
Table 22.6.1.1 LCD Display Control
DSPC[1:0]
LCD display
0x3
All off (static)
0x2
All on (dynamic)
0x1
Normal display
0x0
Display off
(Default: 0x0)
Set DSPC[1:0] to 0x1 to display normally. However, the clock must be supplied in advance (see Section 22.3).
When “Display off” is selected, the drive voltage supply from the LCD system voltage regulator is disabled and all
the V
C1
to V
C5
pins go to V
SS
level.
All on/off display is achieved by directly changing the LCD drive waveform to on or off and it does not affect the
display memory data. The COM pins output a dynamic drive waveform when “All on” is selected or output a static
drive waveform when “All off” is selected. This facility allows the program to blink screen without altering the
display memory data.
DSPC[1:0] is reset to 0x0 (display off) after initial resetting.
DSPC[1:0] is not reset to 0x0 (display off) on execution of a slp command. DSPC[1:0] should be reset to 0x0 (display
off) via software before executing a slp command, since switching to SLEEP mode with the LCD display left on
will degrade the LCD.
22.6.2 LCD Contrast Adjustment
The LCD contrast can be adjusted in 16 steps. This facility is achieved to control the V
C1
to V
C5
voltages output
from the LCD system voltage regulator.
∗
LC[3:0]
: LCD Contrast Adjustment Bits in the LCD Contrast Adjust (LCD_CADJ) Register (D[3:0]/0x50a1)
Table 22.6.2.1 LCD Contrast Adjustment
LC[3:0]
Contrast
0xf
High (dark)
0xe
↑
:
:
0x1
↓
0x0
Low (light)
(Default: 0x0)
At initial reset, LC[3:0] is set to 0x0. Initialize LC[3:0] with software to set the display to the desired contrast.
22.6.3 Reverse Display
The display can be reversed (turns black pixels white and vice versa) simply by manipulating a control bit without
altering the display memory data. Setting DSPREV (D4/LCD_DCTL register) to 0 reverses the display, and setting
it to 1 returns the display to normal.
∗
DSPREV
: Reverse Display Control Bit in the LCD Display Control (LCD_DCTL) Register (D4/0x50a0)
However, the display cannot be reversed when “All off” is selected with DSPC[1:0] (D[1:0]/LCD_DCTL register).
The display can be reversed when “All on” is selected.
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 ...