Page 22
Epson Research and Development
Vancouver Design Center
S1D13503
Programming Notes and Examples
X18A-G-002-06
Issue Date: 01/01/30
3.2.2 Look-Up Table Description
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The Look-Up Table (LUT, or palette) 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; a pixel value of 7 would point to the eighth LUT
entry.
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The value inside each LUT entry represents the intensity of the given color or gray shade. This value ranges between
0 and 0Fh.
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The S1D13503 Look-Up table is linear; increasing the LUT entry number results in a lighter color or gray shade. For
example, a LUT entry of 0Fh into the red Look-Up entry will always result in a bright red output. An entry of 00h
into a Look-Up entry will always result in the removal of this color (black if monochrome).
•
Because LUT entries represent the actual colors shown on the LCD panel, pixel values indirectly select which color
or gray shade to display.
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When the number of bits in a pixel is less than 4, there are several different LUT configurations based on whether the
display is monochrome or color, and the number of gray shades or colors.
3.2.2.1 Color Mode
In color mode, the S1D13503 supports three 16 position, 4 bit wide color LUTs (red, green, and blue). Depending on the
selected pixel size, these LUTs will provide from 1 to 4 banks.
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2 bits-per-pixel (4 colors)
In this format the pixel is an index into the red, green, and blue LUTs. Each color LUT supports 4 banks (see Section
3.2.5, “Four Colors (Two Bits/Pixel in Color Mode)” on page 28).
•
4 bits-per-pixel (16 colors)
In this format the pixel is an index into the red, green, and blue LUTs. Each color LUT supports only one bank (see
Section 3.2.7, “Sixteen Colors (Four Bits/Pixel in Color Mode)” on page 31).
•
8 bits-per-pixel (256 colors)
In this format the pixel is divided into three parts: 3 bits for red, 3 bits for green, and 2 bits for blue. If the red, green,
and blue LUTs were programmed to show a linear increase in intensity of the given color, the 8 bit pixel describes the
intensity of the given set of colors. For example, a pixel value of 00h would be black, E0h would be bright red, 1Ch
would be bright green, and 03h would be bright blue. Because there are 16 entries for each color LUT, the S1D13503
provides two red banks, two green banks, and four blue banks in 256 color mode (see Section 3.2.8, “256 Colors
(Eight Bits/Pixel in Color Mode)” on page 32).
Table 3-4: Look-Up Table Configurations
Display Mode
4-bit wide Palette
RED
GREEN
BLUE
Black & White
4-level gray
4 banks of 4
16-level gray
1 bank of 16
4 color
4 banks of 4
4 banks of 4
4 banks of 4
16 color
1 bank of 16
1 bank of 16
1 bank of 16
256 color
2 banks of 8
2 banks of 8
4 banks of 4
Indicates the palette is not used for that display mode
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