ra8802 RAIO Technology Inc., ra8802 Datasheet - Page 20

• Manufacturer Part Number: ra8802
• Description: Character/graphic Lcd Controller
• Manufacturer: RAIO Technology Inc.

Version 1.3
RAiO
6.3 Display Data RAM (DDRAM)
6.4 Display Timing Generator
6.5 LCD Display
TECHNOLOGY INC.
and minimum limit. When appreciate setup with Register [10h] bit3, [F0h] bit3 and [60h, 70h] the
RA8802/8820 can offer powerful variety meet various application.
The Register [28h, 38h, 48h, 58h] of RA8802 can satisfy various LCD display from (0,0)~(320,240) pixels.
The Register [28h, 38h, 48h, 58h] of RA8820 can satisfy various LCD display from (0,0)~(240,160) pixels.
Powerful INT via Register [A0h, B0h, B8h] reduce MCU polling cycle to Interrupt interactive utility.
Therefore we can use low end MCU to cost down and help the whole system reduce BOM cost.
Display data RAM (DDRAM) stores bit mapping pixel data and display attribute codes for displaying data.
A full-size font is displayed using two bytes, and a half-size font is displayed using one byte. DDRAM
displays only that data stored within the range corresponding to the DDRAM. Data stored outside the
range is ignored. Refer to combined display of full-size and half-size characters for details on character
codes stored in DDRAM.
The display data RAM stores pixel data for LCD. For RA8802, it is a 320 column by 240 row addressable
array maximum. For RA8820, it is a 240 column by 160 rows. The time required to transfer data is very
short. The microprocessor writes and reads data to/from the RAM through data bus. As the LCD
controller operates independently, data can be written into the RAM at the same time as the data is being
displayed, without the LCD to flicker. If apply to the character/graphical mix mode. RA8802/8820 can
easy store and display the data/picture which user desired.
The main function is to generate Frame (FRM), Latch Pulse (LP), YD and Data Bus signals for external
LCD driver IC. RA8802/8820 could both support 4-bit and 8-bit LCD driver interface. SYS_LD is for LCD
driver data bus selection. Non-Pull when 8-bit LCD driver is used. Pull low when 4-bit LCD driver is used.
The RA8802 supports up to 320x240 LCD Panel, and RA8802 supports up to 240x160. Users could
D7 D6 D5 D4 D3 D2 D1 D0
1 1
Display Data RAM
1 0 0 1 1
Figure 6-3 Display data to LCD map
0
20/20
0
1
2
Display On LCD
Segment
Character/Graphic LCD Controller
3
4
5
6
RA8802/8820
7 …..
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