SPC8106 S-MOS Systems, SPC8106 Datasheet - Page 164

• Manufacturer Part Number: SPC8106
• Description: LCD/CRT VGA CONTROLLER
• Manufacturer: S-MOS Systems

10.6 LCD Gray Scale/Color Lookup Table Architecture
Hardware Functional Specification
SP1-122
0 = [19G + 9R + 4B] / 32
1 = G5 G4 G3 G2 G1 G0
weighting function
select from
AUX[01] bit 4
pixel data
+ color select bits
from Attributes
Controller
TSTN Config Bit 3
(configuration bit
AUX[02] bit 6)
S-MOS Systems, Inc. • Tel: [phone] • Fax: [phone] • http://www.smos.com
8 bit
lookup
table index
lookup table
data register
3C9
1st access
256 x 6 bit
lookup table 2
256 x 6 bit
lookup table 1
Figure 40 : LCD Gray Scale Lookup Table Architecture
X X
CPU read/write data
FA
FB
FC
FD
FE
FF
FA
FB
FC
FD
FE
FF
D5 D4
Weighting Function
0
1
2
3
4
5
0
1
2
3
4
5
(on Write data)
Gray Scale
2nd access
D3 D2 D1 D0
MUX
X12-SP-001-07
2
2
4
4
3rd access
Note:
the upper 4 bits of the 6 bit LUT
output are used to generate 1 of 16
FRM gray shades. The lower two bits
are used to generate the dithering
pattern in mode 13h for 64 grays.
16 gray
16 gray
16 gray
shade
shade
shade
FRM
dither
FRM
FRM
Legend:
Circuit activated only when
monochrome LCD panel
is selected
Circuit activated only when
color LCD panel is selected
Red pixel
output to Color
LCD panel
pixel output to
external RAMDAC
for CRT display
Pixel output to
monochrome
LCD panel
Green pixel output
to Color LCD panel
Blue pixel
output to Color
LCD panel
or
411-1.0
SPC8106