User`s manual

3: DISPLAY BUFFER
S1D13504 PROGRAMMING NOTES EPSON 2-9
AND EXAMPLES (S19A-G-002-06)
In 8 bpp mode, the 16 entry LUTs are logically split into 2 groups of 8 entries for both Red and
Green as follows:
Bank 0 = Indexes 00–07h
Bank 1 = Indexes 08–0Fh
For Blue the 16 entry LUT is logically split into 4 groups of 4 entries as follows:
Bank 0 = Indexes 00–03h
Bank 1 = Indexes 04–07h
Bank 2 = Indexes 08–0Bh
Bank 3 = Indexes 0C–0Fh
The bank select bits only affect data output. CPU access to the LUT indexes are done directly as in
the example below:
To program index 3 of the current LUT, with Green bank select bits set to 11b and 2 bpp gray shade
mode selected, you would program LUT address to [ [ 3 (bank select value) * 4 (entries in LUT ] +
3 (index to modify) - 1 (to zero-base the value) ] = 14 (0Eh).
3.3.2 Look-Up Table Organization
• The Look-Up Table (LUT) 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.
• The value inside each LUT entry represents the intensity of the given color or gray shade. This
value ranges between 0 and 0Fh.
• The S1D13504 LUT is linear; increasing the LUT 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 out-
put.
Color Modes
In color mode, the S1D13504 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.
1 bpp Color
In 1 bpp color mode, the LUT is limited to a single 2 entry bank per color. The LUT bank select bits
have no effect in this mode.
Table 3-7 Look-Up Table Configurations
Display Mode
4-Bit Wide Look-Up Table Effective Grays/Colors
on an Passive PanelRED GREEN BLUE
1 bpp gray
1 bank of 2 2 gray shades
2 bpp gray 4 banks of 4 4 gray shades
4 bpp gray 1 bank of 16 16 gray shades
8 bpp gray 2 banks of 8 8 gray shades
15 bpp gray 16 gray shades
16 bpp gray 16 gray shades
1 bpp color 1 bank of 2 1 bank of 2 1 bank of 2 2 colors
2 bpp color 4 banks of 4 4 banks of 4 4 banks of 4 4 colors
4 bpp color 1 bank of 16 1 bank of 16 1 bank of 16 16 colors
8 bpp color 2 banks of 8 2 banks of 8 4 banks of 4 256 colors
15 bpp color 4096 colors*
16 bpp color 4096 colors*
* On a TFT panel the effective colors are determined by the interface width (i.e. 9-bit=512, 12-bit=4096,
18-bit=64K colors). Passive panels are limited to 12-bits (4096) through the frame rate modulator.
Indicates the Look-Up Table is not used for that display mode.