Samsung Exynos 5 User Manual

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-19  
15.3.3.1.13 4-bpp Display (Palette) 
 
 
NOTE: AEN = specifies the transparency selection bit when you select palette output format with alpha channel in 
WPALCON register.  
AEN: 0 = selects ALPHA0 
AEN: 1 = selects ALPHA1 
When the per-pixel blending is set, it blends with the alpha value that AEN selects. 
SFR selects the alpha value as ALPHA0_R, ALPHA0_G, ALPHA0_B, ALPHA1_R, ALPHA1_G, and ALPHA1_B.  
Refer to SFR section for more...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-20  
15.3.3.1.14 2-bpp Display (Palette) 
 
NOTE: AEN = specifies the transparency selection bit when you select palette output format with alpha channel in 
WPALCON register. 
AEN: 0 = selects ALPHA0  
AEN: 1 = selects ALPHA1   
When the per-pixel blending is set, it blends with the alpha value that AEN selects. 
SFR selects the alpha value as ALPHA0_R, ALPHA0_G, ALPHA0_B, ALPHA1_R, ALPHA1_G, and ALPHA1_B. 
Refer to SFR section for more...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-21  
Figure 15-4 illustrates the 16-bpp (5:6:5) Display Types 
 
    Figure 15-4   16-bpp (5:6:5) Display Types 
 
 12345
LCD  Panel
16BPP 5: 5:5+1 Format (Non-Palett e)
A[ 31]  A[ 30]  A[29]  A[ 28]  A[27]  A[26] A[25]  A[ 24]  A[23]  A[22]  A[ 21]  A[20]  A[ 19] A[18]  A[ 17]  A[16]
R4R3R2R1R0G4G3G2G1G0R4B3B2B1B0I
A[ 15]    A[14]  A[ 13]  A[12]  A[ 11]  A[ 10]   A[ 9]     A[8]     A[ 7]      A[6]       A[5]     A[ 4]     A[3]     A[ 2]...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-22  
15.3.4 Color Space Conversion  
These tables describe examples of color scheme conversion: 
 Color Space Conversion YCbCr to RGB (CSCY2R) 
 Color Space Conversion RGB to YCbCr (CSCR2Y) 
15.3.4.1 Color Space Conversion YCbCr to RGB (CSCY2R) 
 
NOTE: Wide indicates that the RGB data contains a nominal range from 0 to 255. Alternatively, Narrow indicates that the 
RGB data contains a nominal range from 16 to 235. 
 
Coefficient...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-23  
15.3.4.2 Color Space Conversion RGB to YCbCr (CSCR2Y) 
 
NOTE: Wide indicates that the RGB data contains a nominal range from 0 to 255. Alternatively, Narrow indicates that the 
RGB data contains a nominal range from 16 to 235. 
 
Coefficient Approximation 
0.257 = (2^6 + 2^1) >> 8    0.183 = (2^5 + 2^3 + 2^2 + 2^1 + 2^0) >> 8 
0.504 = (2^7 + 2^0) >> 8    0.614 = (2^7 + 2^4 + 2^3 + 2^2 + 2^0) >> 8 
0.098 = (2^4 + 2^3 + 2^0) >> 8...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-24  
15.3.5 Palette Usage 
15.3.5.1 Palette Configuration and Format Control 
The display controller supports 256-color palette to select color mapping. You can select up to 256 colors from 32-
bit colors by using below formats. 
A 256-color palette consists of 256 (depth)  32-bit SPSRAM. It supports 8:8:8, 6:6:6, 5:6:5 (R: G: B), and other 
formats.  
For Example:  
Refer to A:5:5:5 format, Write palette, as described in Table 15-2....

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-25  
Table 15-4 describes the 19-bpp (A: 6:6:6) palette data format. 
Table 15-4   19-bpp (A: 6:6:6) Palette Data Format 
 
Table 15-5 describes the 16-bpp (A: 5:5:5) palette data format. 
Table 15-5   16-bpp (A: 5:5:5) Palette Data Format 
 
 
15.3.5.2 Palette Read/Write 
Do not access palette memory when the Vertical Status (VSTATUS) register is ACTIVE. Enable VSTATUS to 
perform Read/Write operation on the palette. 
 
  INDEX/Bit...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-26  
15.3.6 Window Blending 
15.3.6.1 Overview  
The main function of the VPRCS module is window blending. The display controller consists of five window layers 
(win0 to win4).  
 
Example of Application: 
The system uses:  
win0 as OS window, full TV screen window, and so on 
win1 as small (next channel ) TV screen with win2 as menu 
win3 as caption 
win4 as channel information 
win3 and win4 have color limitation when it uses color index...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-27  
Blending Equation  
 
Win01 (R, G, B) = Win0 (R, G, B) x b1 + Win1 (R, G, B) x a1 
Win012 (R/G/B) = Win01 (R/G/B) x b2 + Win2 (R/G/B) x a2 
Win0123 (R/G/B) = Win012 (R/G/B) x b3 + Win3 (R/G/B) x a3 
WinOut (R/G/B) = Win0123 (R/G/B) x b4 + Win4 (R/G/B) x a4 
 
where,  
Win0(R) = Window 0s Red data 
Win0(G) = Window 0s Green data 
Win0(B) = Window 0s Blue data 
Win1(R) = Window 1s Red data 
... 
b1 = Backgrounds Data blending equation1...

Samsung Confidential  
Exynos 5250_UM 15 Display Controller 
 15-28  
Figure 15-5 illustrates the blending equation. 
 
    Figure 15-5   Blending Equation 
 
< Default blending equation > 
 
Data blending>  
B = B  (1-alphaA) + A  alphaA 
 
Alpha value blending> 
alphaB = 0 (= alphaB x 0 + alphaA  0)  
 
 Blending
alphaAalphaBAB
alphaB’B’
B’           =     a x A  +  b x B
alphaB’  =     p x alphaA  +  q x alphaB
a/b/p/q = 0
or    1
or    alphaA
or    1 - alphaA
or    alphaB
or    1 - alphaB
or    A...