ML51/ML54/ML56
Sep. 01, 2020
Page
613
of 719
Rev 2.00
ML
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/ML
54
/ML
5
6 S
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TECHNI
CA
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M
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ML51/M
L54
/M
L56
Series
Tec
hnical Reference
Manual
DUTY[1:0] = 00 (4COM)
LCDPTR = 0x0A ~ 0x11
LCDDAT = 0xFF
(7) (6) (5) (4) (3) (2) (1) (0)
L
C
D
P
T
R
[4
:0
]
Display Off
Display On
C
O
M
0
C
O
M
1
C
O
M
2
C
O
M
3
C
O
M
4
C
O
M
5
C
O
M
6
C
O
M
7
If COM1 and SEG15 is the same
pin, MFP defined this pin as COM1
DUTY[1:0] = 10 (8COM)
LCDPTR = 0x0A ~ 0x11
LCDDAT = 0xFF
(7) (6) (5) (4) (3) (2) (1) (0)
L
C
D
P
T
R
[4
:0
]
C
O
M
0
C
O
M
1
C
O
M
2
C
O
M
3
C
O
M
4
C
O
M
5
C
O
M
6
C
O
M
7
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
(7) (6) (5) (4) (3) (2) (1) (0)
L
C
D
P
T
R
[4
:0
]
C
O
M
0
C
O
M
1
C
O
M
2
C
O
M
3
C
O
M
4
C
O
M
5
C
O
M
6
C
O
M
7
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
DUTY[1:0] = 10 (8COM)
LCDPTR = 0x0A ~ 0x11
LCDDAT = 0xB7
LCDDAT[7:0]
LCDDAT[7:0]
LCDDAT[7:0]
Figure 6.17-2. LCD Register Map Example
The LCD must only be driven with AC voltages. A DC voltage deteriorates the liquid crystal fluid and
hence cannot be energized. Therefore, DC voltage applied to LCD electrodes may harm and destroy
the LCD. The LCD driver waveforms are designed to create 0-Vdd potential across all LCD segments.
ML51/ML54/ML56 Series can drive two types of the LCD waverforms which call TYPE A and TYPE B
by setting LCDCON0[6] bit
If the segment waveform equals an inverted common waveform, then the segment is in ON
state.Following Figure 6.17-3 One Frame of LCD Energized shows the two type of the LCD driver one
COM and one SEG waveform ON / OFF state and the enegized zone.
COM0
SEG0
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
COM0
SEG0
Odd Frame
Even Frame
TYPE A
TYPE B
Frame 1
Frame 2
Frame 1
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
COM0xSEG0
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
-1/4V
LCD
-2/4V
LCD
-3/4V
LCD
-V
LCD
COM0xSEG0
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
-1/4V
LCD
-2/4V
LCD
-3/4V
LCD
-V
LCD
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
V
LCD
3/4V
LCD
2/4V
LCD
1/4V
LCD
0
LCD Energized Zone
LCD ON
LCD Un-energized Zone
LCD OFF
LCD Energized Zone
LCD ON
LCD Un-energized Zone
LCD OFF
Figure 6.17-3 One Frame of LCD Energized
The accompanying timing diagrams depict the display driver signals generated by the microcontroller
for various values of bias. Diagrams show the default 1/8 duty waveforms for illustration.