SED1374 Datasheet, PDF (118/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

Page 22
Epson Research and Development
Vancouver Design Center
8 Bpp Color
When the SED1374 is configured for 8 bit-per-pixel color mode, 8 colors from red and
green and 4 colors from the blue active banks are displayed. The eight red, eight green and
four blue entries can be set to any color.
The SED1374 LUT has four bits (16 levels) of intensity control per primary color while a
standard VGA RAMDAC has six bits (64 levels). This four to one difference has to be
considered when attempting to match colors between a VGA RAMDAC and the SED1374
LUT. (i.e. VGA levels 0 - 3 map to LUT level 0, VGA levels 4 - 7 map to LUT level 1...
etc.).
The following table shows LUT values that approximate the default 256 color VGA palette.
Table 4-8: Suggested LUT Values to Simulate VGA Default 256 Color Palette
Index
Red
Green
Blue
00
00
00
00
01
02
02
05
02
04
04
0A
03
06
06
0F
04
09
09
00
05
0B
0B
00
06
0D
0D
00
07
0F
0F
00
08
00
00
00
...
00
00
00
0F
00
00
00
Normally unused entries
SED1374
X26A-G-002-02
Programming Notes and Examples
Issue Date: 99/04/27