GM5020 Datasheet, PDF (66/86 Pages) List of Unclassifed Manufacturers – Graphics Processing IC providing high-quality images for LCD monitors and other pixelated displays

Genesis Microchip
gm5020 / gm5020-H Data Sheet
Pixels mapped to a “1” are foreground pixels. The foreground index value (FG) programmed
into the color index table is then used as the index into the OSD CLUT. Pixels mapped to a “0”
are background pixels. The background color for the character is determined by the window
region or the background color index value (BG) programmed into the color index table.
Figure 48 shows the font definition for a rotated character in the font SRAM.
CHARMAP_FONTX=16
Font BitMask
0000000000000000
0000000000000000
0001110000001100
0011111100001100
0011000110001100
1
CHARMAP_FONTY=12
0011000011001100
0011000001101100
0011000000111100
0
0001110000011100
0000110000001100
0000000000000000
0000000000000000
Figure 48. Rotated SRAM Resident Font
Two Bits Per Pixel SRAM Resident Fonts
Typically there is storage space for 128 or more two bit per pixel SRAM resident fonts.
Two bit per pixel SRAM based fonts support up to three foreground colors per character and one
background color per character. Figure 49 shows a two bit per pixel SRAM based font definition
for a character.
CHARMAP_FONTX=12
Font BitMask
000000000000000000000000
000000000010101010000000
000000000101010101100000
000000010101010101011000
000001010100000001010110
000001010000000000010110
000001010000000001010110
000000000000000101011000
CHARMAP_FONTY=18 _{000000000000010101100000}
000000000001010110000000
01
000000000101011000000000
000000010101101010101010
00
000001010101010101010110
000001010101010101010110
10
000000000000000000000000
111111111111111111111111
11
000000000000000000000000
Figure 49. User Define-able SRAM Resident Font
When using 2-bits per pixel SRAM resident fonts, the designer defines each pixel using a 2-bit
code. Bit codes “11”, “10”, and “01” are mapped to foreground colors 3, 2 and 1 respectively. Bit
February 2002
57
C5020-DAT-01Q