100
EPSON
E0C88832/88862 TECHNICAL MANUAL
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (LCD Controller)
5.11.6 Display control
The display status of the built-in LCD driver and
the contrast adjustment can be controlled with the
built-in LCD controller. The LCD display status can
be selected by display control registers LCDC0 and
LCDC1. Setting the value and display status are
shown in Table 5.11.6.1.
Table 5.11.6.1 LCD display control
All the dots in the LCD display can be turned on or
off directly by the drive waveform output from the
LCD driver, and data in the display memory is not
changed. Also, since the common terminal at this
time is set to static drive when all the dots are on
and is set to dynamic drive when they are off, this
function can be used as follows:
(1) Since all dots on is binary output (V
C5
and V
SS
)
with static drive, the common/segment termi-
nal can be used as a monitor terminal for the
OSC1 oscillation frequency adjustment.
(2) Since all dots off is dynamic drive, you can
brink the entire LCD display without changing
display memory data.
LCDC1
LCDC0
LCD display
1
1
0
0
1
0
1
0
All LCDs lit (Static)
All LCDs out (Dynamic)
Normal display
Drive OFF
LC3
LC0
Contrast
1
1
1
:
0
0
0
1
0
1
:
0
1
0
Dark
Light
LC1
1
1
0
:
1
0
0
LC2
1
1
1
:
0
0
0
↑
↓
Selecting LCD drive OFF turns the LCD drive
power circuit OFF and all the V
C1
–V
C5
terminals go
to V
SS
level. However, if external power supply has
been selected by the mask option, the V
C1
–V
C5
shift
to floating status when drive is turned OFF.
Furthermore, when the SLP instruction is executed,
registers LCDC0 and LCDC1 are automatically
reset to "0" (set to drive off) by hardware.
The LCD contrast can be adjusted in 16 stages. This
adjustment is done by the contrast adjustment
register LC0–LC3, and the setting values corre-
spond to the contrast as shown in Table 5.11.6.2.
However, if external power supply has been
selected by the mask option, the contrast adjust-
ment register LC0–LC3 is ineffective and contrast
adjustment cannot be done.
Table 5.11.6.2 LCD contrast adjustment
Note: Fixing the LCD contrast is not recommended.
A contrast adjustment function should be
included in the software.
Summary of Contents for 0C88832
Page 6: ......