ra8835a RAIO Technology Inc., ra8835a Datasheet - Page 54

• Manufacturer Part Number: ra8835a
• Description: Dot Matrix Lcd Controller
• Manufacturer: RAIO Technology Inc.

RAiO TECHNOLOGY INC.
Version 1.0
SAG
Character code
+ROW select
address
CG RAM address
CG RAM address
Character code
7-16 Setting Character Generator Address
+ROW select
address
7-16-1 M1 = 1
SAG
The CG RAM addresses in the VRAM address space are not mapped directly from the address in the
SAG register. The data to be displayed is at a CG RAM address calculated from SAG + character
code + ROW select address. This mapping is shown in Table-22A and –22B.
The RA8835A series automatically converts all bits set in bit 6 of character code for CG RAM 2 to
zero. Because of this, the CG RAM data areas become contiguous in display memory.
When writing data to CG RAM:
Note: Lines = 1: lines in the character bitmap
Table-22B: Character Fonts, 9
• Calculate the address as for M1 = 0.
• Change bit 6 of the character code from “1” to “0”.
Table-22A: Character Fonts, Number of Lines
VA15 VA14 VA13 VA12 VA11 VA10 VA9 VA8 VA7 VA6 VA5 VA4 VA3 VA2 VA1 VA0
VA15 VA14 VA13 VA12 VA11 VA10 VA9
A15 A14 A13 A12 A11 A10 A9
A15 A14 A13 A12 A11 A10 A9
0
0
0
0
Lines = 2: lines in the character bitmap
0
0
0
0
0
0
0
0
Figure 7-28: Row Select Address
0
0
0
0
D7
0
0
0
D6
≤
D7
0
0
54/88
Number of Lines
D5
D6
0
0
VA8
A8
A8
D4
D5
0
0
≤
≤
9
8
VA7
A7
A7
D3
D4
0
0
≤
≤
8 (M2 = 0, M1 = 0)
VA6
A6
D2
A6
D3
0
0
16 (M2 = 1, M1 = 0)
VA5
A5
D1
A5
D2
0
0
Dot Matrix LCD Controller
A4
VA4
D0
A4
D1
0
0
A3
VA3
R3
A3
D0
0
0
RA8835A
www.raio.com.tw
A2
VA2
R2
A2
R2
0
0
A1
VA1
R1
A1
R1
0
0
A0
VA0
R0
A0
R0
0
0