S3C44B0X Samsung, S3C44B0X Datasheet - Page 324



Manufacturer Part Number

Specifications of S3C44B0X

Table 15-1. Relation between VCLK and CLKVAL(STN, HCLK=60MHz)
The LCD controller within S3C2400 supports 8-bit color mode (256 color mode), 12-bit color mode (4096 color mode),
4 level gray scale mode, 16 level gray scale mode as well as the monochrome mode. When the gray or color mode
is needed, the implementation of the shades of gray level or color should be followed by time-based dithering
algorithm and FRC(Frame Rate Control) method can be used to implement the shades of gray or color from which
selection can be made by using a programmable lockup table, which will be explained later. The monochrome mode
bypasses these modules(FRC and lookup table) and basically serializes the data in FIFOH (and FIFOL if a dual scan
display type is used) into 4-bit (or 8-bit if a 4-bit dual scan or 8-bit single scan display type is used) streams by
shifting the video data to the LCD driver.
The following sections describe the operation on gray mode and color mode in terms of the lookup table and FRC.
Lookup Table
The S3C2400 can support the palette table for various selection of color or gray level mapping. This kind of selection
gives users flexibility. The lookup table is the palette which allows the selection on the level of color or gray(Selection
on 4-gray levels among 16 gray levels in case of gray mode, selection on 8 red levels among 16 levels, 8 green levels
among 16 levels and 4 blue levels among 16 levels in case of color mode). In other words, users can select 4 gray
levels among 16 gray levels by using the lookup table in the 4 gray level mode. The gray levels cannot be selected in
the 16 gray level mode; all 16 gray levels must be chosen among the possible 16 gray levels. In case of 256 color
mode, 3 bits are allocated for red, 3 bits for green and 2 bits for blue. The 256 colors mean that the colors are formed
from the combination of 8 red, 8 green and 4 blue levels(8x8x4 = 256). In the color mode, the lookup table can be
used for suitable selections. Eight red levels can be selected among 16 possible red levels, 8 green levels among 16
green levels, and 4 blue levels among 16 blue levels. In case of 4096 color mode, of course there is no selection as
in the 256 color mode.
Gray Mode Operation
Two gray modes are supported by the LCD controller within the S3C2400: 2-bit per pixel gray (4 level gray scale) or
4-bit per pixel gray (16 level gray scale). The 2-bit per pixel gray mode uses a lookup table, which allows selection on
4 gray levels among 16 possible gray levels. The 2-bit per pixel gray lookup table uses the BULEVAL[15:0] in
BLUELUT(Blue Lookup Table) register as same as blue lookup table in color mode. The gray level 0 will be denoted
by BLUEVAL[3:0] value. If BLUEVAL[3:0] is 9, level 0 will be represented by gray level 9 among 16 gray levels. If
BLUEVAL[3:0] is 15, level 0 will be represented by gray level 15 among 16 gray levels, and so on. As same as in the
case of level 0, level 1 will also be denoted by BLUEVAL[7:4], the level 2 by BLUEVAL[11:8], and the level 3 by
BLUEVAL[15:12]. These four groups among BLUEVAL[15:0] will represent level 0, level 1, level 2, and level 3. In 16
gray levels, of course there is no selection as in the 4 gray levels.
60 MHz/4
15.0 MHz
60 MHz/6
10.0 MHz
60 MHz/2046
29.3 kHz

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