Epson S1D13704 Technical Manual page 118

Page 22
Table 4-8: Suggested LUT Values to Simulate VGA Default 256 Color Palett e
S1D13704
X26A-G-002-03
8 Bpp Color
When the S1D13704 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 S1D13704 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 S1D13704
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.
Index
00
01
02
03
04
05
06
07
08
...
0F
Red Green Blue
00 00 00
02 02 05
04 04 0A
06 06 0F
09 09 00
0B 0B 00
0D 0D 00
0F 0F 00
*
00 00 00
00 00 00
00 00 00
Normally unused entries
Epson Research and Development
Vancouver Design Center
Programming Notes and Examples
Issue Date: 01/02/12