RA8835A
Version 1.0
Dot Matrix LCD Controller
The basic screen configuration of the RA8835A series is as a single text screen or as overlapping
text and graphics screens. The graphics screen uses eight times as much display memory as the
text screen. Figure 7-11 shows the relationship between the virtual screens and the physical
screen.
7-10-2 Display Address Scanning
The RA8835A series scans the display memory in the same way as a raster scan CRT screen.
Each row is scanned from left to right until the address range equals C/R. Rows are scanned
from top to bottom.
In graphics mode, at the start of each line, the address counter is set to the address at the start of
the previous line plus the address pitch, AP.
1
‧
SAD
SAD+1
SAD+2
SAD+C/R
‧
8
9
‧
SAD+AP SAD+AP SAD+AP
+1 +2
SAD+AP
+C/R
‧
16
17
‧
‧
SAD+2AP
24
‧
‧
‧
C/R
WS=0,FX=8,FY=8
Figure 7-12: Character Position Parameters
Note: One byte of display memory corresponds to one character.
1
SAD
SAD+1
SAD+2
SAD+C/R
SAD+AP SAD+AP SAD+AP
2
3
SAD
SAD+1
SAD+2
SAD+AP
+C/R
+1
+2
Line 1
AP
AP
SAD+2AP
SAD+C/R
‧
‧
‧
‧
SAD+AP
SAD+AP+1
Line 2
Line 3
‧
‧
SAD+AP+C/R
SAD+2AP
C/R
WS=0,FX=8
Figure 7-13: Character Parameters vs. Memory
Note: One bit of display memory corresponds to one pixel.
RAiO TECHNOLOGY INC.
www.raio.com.tw
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RAIO [ RAIO TECHNOLOGY INC. ]
