HD66766R Datasheet, PDF (58/97 Pages) Hitachi Semiconductor – 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors

HD66766R
Rev. 1.0-1 / September 2002
Grayscale Palette
The HD66766R incorporates a grayscale palette to simultaneously display 65K of the 140,608 possible
colors. The grayscales consist of 32 6-bit palettes. The 52-stage grayscale levels can be selected from
the 6-bit palette data.
For the display data, the four-bit data in the GRAM written from the microcomputer is used.
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.
Graphic RAM ( GRAM )
SB
LSB
Display data
R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0
<RGB>
Palette
5
6
5
"00000" 0
PK0 (5 0)
00
00
"01011"
0
0
1
PK11 (5 0)
001
PK22 (5 0)
1
"10110" _{0 1}
1
1
10
PK1 (5 0)
PK12 (5 0)
PK23 (5 0)
"00001"
0
00
01
1
01100 ₀
1
01
0
0 "10111" 1
0
0
0 00
"00010" ₀
PK2 (5 0)
00
11
0 ^{"01101" 0}
1
PK13 (5 0)
010
PK24 (5 0)
0 ^"11000" _{1 0}
0
0
10
"00011" 0
PK3 (5 0)
01
00
0 ^"01110" ₀
PK14 (5 0)
1011
0
"11001" ₁
PK25 (5 0)
00
1
00
PK4 (5 0)
PK15 (5 0)
PK26 (5 0)
"00100" 0
01
01
0 "01111" ₀
1
0
1
1
1
"11010" ₁
0
0
1 10
"00101" ₀
PK5 (5 0)
01
10
"10000"
0
0
1
PK16 (5 0)
100
PK27 (5 0)
0 ^{"11011" 1 0}
1
0
00
"00110"
0
"00111" ⁰
PK6(5 0)
0
1
PK7 (5
0)¹
1
0
1
11
PK8 (5 0)
0 ^{"10001" 0}
1 "10010" 0
PK17(5 0)
1100
PK18 (5 0)
1101
PK19 (5 0)
"11100"
PK28(5 0)
1
10 1
0 11
0
"11101" ₁
PK29 (5 0)
01
1
1
0
PK30 (5 0)
"01000" ₀
10
00
0 "10011" ⁰
1
10
1
1 _{"11110" 1 1}
0
0 01
"01001" ₀
PK9 (5 0)
10
00
1 ^{"10100" 0}
1
PK20 (5 0)
110
PK31 (5 0)
0 "11111" ₁
1
0
1
00
"01010" ₀
PK10 (5 0)
10
0
1
0 _{"10101" 0}
PK21 (5 0)
1110
1
Palette register
Initialized value
6
5
5
5
52 gray scale control
<R>
32
LCD Driver
52 gray scale control
<G>
32
32 64 gray scale
64
LCD Driver
52 gray scale control
<B>
32
LCD Driver
R
G
B
Figure 44 Grayscale Palette Control
58