ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 77

• Manufacturer Part Number: ra8806
• Description: Two Layers Character/graphic Lcd Controller
• Manufacturer: RAIO Technology Inc.

Preliminary Version 1.2
RAiO
TECHNOLOGY INC.
6-10-1-6 Line Gap
6-10-2 Gray Scale Display
The RA8806 provide Line Gap feature. Especially in Chinese display, if add some space in each line
will look better. The range of line gap is 1 ~ 16 pixel. Once the line gap is setup, the cursor will
automatically move to property position for each line.
Setting the low nibble of the register CHWI, user can adjust the line gap. To deserve to be
mentioned, when RA8806 operating in 90 degree mode, the line gap is either 0 pixel or 8 pixels, no
matter what the font size. The selection of two conditions is according to Bit-3 of the register CHWI.
The RA8806 also provide 4-gray-scale display implemented by FRC method. In gray level display
mode, RA8806 combines the data of DDRAM1 and DDRAM2 as a gray picture. Each gray pixel
occupies 2 bits of DDRAM data for display. Data [00b] indicate an empty pixel display and [11b] is
solid display. [01b] & [10b] will be time sharing as 1/3 and 2/3 lightness. Please refer to Figure 6-46.
According to the data write order, RA8806 support 2 data input methodology for Gray-Scale display.
User can write the data as the same way of mono graphic display.
7 6 5 4 3 2 1 0
7 6 5 4 3 2 1 0
CHWI
1. Horizontal moving first then Vertical, refer Figure 6-47.
2. Vertical moving first then Horizontal, refer Figure 6-48.
Reg.
Bit-a
0
0
1
1
Gray-Scale Display
Bit-b
Bit_Num
0
1
0
1
Figure 6-46 : Mapping Rule of 4-Gray-Scale Display
Bit [7:4]
Bit [3:2]
Gray-Level
1
2
3
4
Set Cursor Height
Set Line Gap
Table 6-26
Description
77/184
3a 3b 2a 2b 1a 1b 0a 0b
3a 3b 2a 2b 1a 1b 0a 0b
Two Layers Character/Graphic LCD Controller
DDRAM1: Display Data RAM #1
DDRAM2: Display Data RAM #2
In Gray-Scale mode, both DDRAM are used.
7a 7b 6a 6b 5a 5b 4a 4b
7a 7b 6a 6b 5a 5b 4a 4b
DDRAM2
Reference
REG[11h]
DDRAM1
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RA8806