hd66765 Renesas Electronics Corporation., hd66765 Datasheet - Page 58

• Manufacturer Part Number: hd66765
• Description: 396-channel Segment Driver With Internal Ram For 4096-color Displays - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

HD66765
Grayscale Palette
The HD66765 incorporates a grayscale palette to simultaneously display 4,096 out of 13,824 possible
colors. The grayscales consist of sixteen five-bit palettes. The 24-stage grayscale levels can be selected
from the five-bit palette data.
In this palette, a pulse-width control system (PWM) is used to eliminate flicker in the LCD display. The
time over which the LCDs are switched on is adjusted according to the level and grayscales are displayed
so that flicker is reduced and grayscales are clearly displayed.
Display data
<RGB> Palette
"0000"
"0001"
"0010"
"0011"
"0100"
"0101"
"0110"
"0111"
MSB
R
24 grayscale ontrol
3
PK
PK
PK
PK
PK
PK
PK
PK
R
LCD driver
04
14
24
34
44
54
64
74
Figure 44 Grayscale Palette Control
2
< R >
R
PK
PK
PK
PK
PK
PK
PK
PK
4
5
R
03
13
23
33
43
53
63
73
1
PK
PK
PK
PK
PK
PK
PK
PK
R
02
12
22
32
42
52
62
72
0
PK
PK
PK
PK
PK
PK
PK
PK
Graphics RAM (GRAM)
01
11
21
31
41
51
61
71
G
24 grayscale ontrol
3
PK
RK
PK
PK
PK
PK
PK
PK
58
03
23
33
43
53
63
73
13
G
LCD driver
LCD
2
< G >
G
G
4
5
1
"1000"
"1001"
"1010"
"1011"
"1100"
"1101"
"1110"
"1111"
G
0
PK
PK
PK
PK
PK
PK
PK
PK
B
104
114
124
134
144
154
84
94
24 grayscale ontrol
3
PK10
PK
PK
PK
PK
PK
PK
PK
B
LCD driver
113
123
133
143
153
83
93
2
< B >
3
PK
PK
PK
PK
PK
PK
B
PK
PK
4
5
B
102
112
122
132
142
152
82
92
1
PK
PK
PK
PK
PK
PK
PK
PK
LSB
B
101
111
121
131
141
151
81
91
0
PK
PK
PK
PK
PK
PK
PK
RK
100
110
120
130
140
150
80
90