HD66421 Datasheet, PDF (40/46 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

Preliminary
Rev. 1.1E '99.02.10
HD66421
Contrast Control and LCD Alternative Drive
Cycle Register (R16): The contrast control
register (figure 44) designates the contrast level of
LCD display. These bits change the voltage which
is supplied to LCD drivers.
The LCD alternative drive cycle register
designates the number of lines that LCD drive
outputs are alternated.
Data bits 7 is unused; they should be set to 0
when written to.
Table 9 Grayscale Levels
GP14 GP13 GP12 GP11 GP10
GP24 GP23 GP22 GP21 GP20
GP34 GP33 GP32 GP31 GP30
GP44 GP43 GP42 GP41 GP40
0
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
0
0
0
1
0
1
0
0
1
1
0
0
0
1
1
1
0
1
0
0
0
0
1
0
0
1
0
1
0
1
0
0
1
0
1
1
0
1
1
0
0
0
1
1
0
1
0
1
1
1
0
0
1
1
1
1
Gray scale
Level
0
1/31
2/31
3/31
4/31
5/31
6/31
7/31
8/31
9/31
10/31
11/31
12/31
13/31
14/31
15/31
GP14 GP13 GP12 GP11 GP10
GP24 GP23 GP22 GP21 GP20
GP34 GP33 GP32 GP31 GP30
GP44 GP43 GP42 GP41 GP40
1
0
0
0
0
1
0
0
0
1
1
0
0
1
0
1
0
0
1
1
1
0
1
0
0
1
0
1
0
1
1
0
1
1
0
1
0
1
1
1
1
1
0
0
0
1
1
0
0
1
1
1
0
1
0
1
1
0
1
1
1
1
1
0
0
1
1
1
0
1
1
1
1
1
0
1
1
1
1
1
Gray scale
Level
16/31
17/31
18/31
19/31
20/31
21/31
22/31
23/31
24/31
25/31
26/31
27/31
28/31
29/31
30/31
1
Table 10 LCD alternative drive cycle
CM1
0
0
0
0
CM0
0
0
0
0
Alternative
Cycle
Frame
7 lines
11 lines
13 lines
Data bit
Set value
7
6
5
4
3
2
1
0
CM1 CM0 CC4 CC3 CC2 CC1 CC0
Figure 44 Contrast Control register (R16)
40