ra8835 Topway Display, ra8835 Datasheet - Page 15

• Manufacturer Part Number: ra8835
• Description: Dot Matrix Lcd Controller
• Manufacturer: Topway Display

RAiO TECHNOLOGY INC.
Version 1.7
Notes:
6-2-1-6 IV
Screen origin compensation for inverse display. IV is usually set to 1. The best way of displaying
inverted characters is to Exclusive-OR the text layer with the graphics background layer. However,
inverted characters at the top or left of the screen are difficult to read as the character origin is at
the top-left of its bitmap and there are no background pixels either above or to the left of these
characters.
The IV flag causes the RA8835 series to offset the text screen against the graphics back layer by
one vertical pixel. Use the horizontal pixel scroll function (HDOT SCR) to shift the text screen 1 to
7 pixels to the right. All characters will then have the necessary surrounding background pixels that
ensure easy reading of the inverted characters. See Section 11-5 for information on scrolling.
IV = 0: Screen top-line correction
IV = 1: No screen top-line correction
6-2-1-7 FX
Define the horizontal character size. The character width in pixels is equal to FX + 1, where FX can
range from 00 to 07H inclusive. If data bit 3 is set (FX is in the range 08 to 0FH) and an 8-pixel font
is used, a space is inserted between characters.
Since the RA8835 series handles display data in 8-bit units, characters larger than 8 pixels wide
must be formed from 8-pixel segments. As Figure 6-6 shows, the remainder of the second eight
bits are not displayed. This also applies to the second screen layer.
1. See Table-24 for further details on setting the C/R and TC/R parameters when using
2. The value of SL when IV = 0 is equal to the value of SL when IV = 1, plus one.
movement
Cursor
range
Continuous movement over whole screen
HEX
Table-3: Horizontal Character Size Selection
00
01
07
Figure 6-5: IV and HDOT SCR Adjustment
↓
HDOT SCR
Character
D
3
0
0
0
↓
Display start point
FX
D
2
0
0
1
↓
Dots 1 to 7
D
1
0
0
1
↓
15/86
D
0
0
1
1
↓
IV
[FX] character
width (pixels)
1
2
↓
8
Above-and-below configuration:
continuous movement over whole screen
Dot Matrix LCD Controller
www.raio.com.tw
RA8835