S1D13506 Datasheet, PDF (254/696 Pages) Epson Company – S1D13506 Color LCD/CRT/TV Controller

Page 20
Epson Research and Development
Vancouver Design Center
The LUT address register selects which of the 256 LUT entries will be accessed. Writing
to this register will select the red bank. After three successive reads or writes to the data
register (REG[1E4h]) this register is automatically incremented by one.
REG[1E4h] Look-Up Table Data Register
LUT Data
Bit 3
LUT Data
Bit 2
LUT Data
Bit 1
LUT Data
Bit 0
n/a
n/a
n/a
n/a
This register is where the 4-bit red/green/blue data is written to/read from. With each
successive read or write the internal bank select is incremented. Three successive reads
from this register will result in reading the red, then the green, and finally the blue values
associated with the index set in the LUT address register.
After the third read the LUT address register is incremented and the internal bank select
points to the red bank again.
4.2 Look-Up Table Organization
• The Look-Up Table treats the value of a pixel as an index into an array of colors or gray
shades. For example, a pixel value of zero would point to the first LUT entry, whereas a
pixel value of seven would point to the eighth LUT entry.
• The value contained in each LUT entry represents the intensity of the given color or
gray shade. This intensity can range in value between 0 and 0Fh.
• The S1D13506 Look-Up Table is linear. This means increasing the LUT entry number
results in a lighter color or gray shade. For example, a LUT entry of 0Fh in the red bank
results in bright red output while a LUT entry of 05h results in dull red.
Display Mode
4 bpp gray
8 bpp gray
15 bpp gray
16 bpp gray
4 bpp color
8 bpp color
15 bpp color
16 bpp color
Table 4-1: Look-Up Table Configurations
4-Bit Wide Look-Up Table
RED
GREEN
16
16
BLUE
16
16
16
256
256
256
Effective Gray
Shades/Colors on an
Passive Panel With
Dithering Disabled
16 gray shades
16 gray shades
16 gray shades
16 gray shades
16 colors
256 colors
4096 colors
4096 colors
= Indicates the Look-Up Table is not used for that display mode
Effective Gray
Shades/Colors on a
Passive Panel With
Dithering Enabled
16 gray shades
16 gray shades
64 gray shades
64 gray shades
16 colors
256 colors
32768 colors
65536 colors
S1D13506
X25B-G-003-03
Programming Notes and Examples
Issue Date: 01/02/06