Samsung S5PC110 Manual page 1140

S5PC110_UM
1.3.6.2 Blending Diagram
The display controller can blend five layers for one pixel at the same time. ALPHA0_R, ALPHA0_G, ALPHA0_B,
ALPHA1_R, ALPHA1_G, and ALPHA1_B registers control the alpha value (blending factor), which are
implemented for each window layer and color (R,G,B).
The example below shows the R (Red) output using ALPHA_R value of each window.
All windows have two kinds of alpha blending value:
•
Alpha value for transparency enable (AEN value ==1)
•
Alpha value for transparency disable (AEN value == 0).
If WINEN_F and BLD_PIX are enabled and ALPHA_SEL is disabled, then AR is chosen using the following
equation:
•
AR = (Pixel(R)'s AEN value == 1'b1) ? Reg( ALPHA1_R ) : Reg( ALPHA0_R );
•
AG = (Pixel(G)'s AEN value == 1'b1) ? Reg( ALPHA1_G ) : Reg( ALPHA0_G );
•
AB = (Pixel(B)'s AEN value == 1'b1) ? Reg( ALPHA1_B ) : Reg( ALPHA0_B );
(where, BLD_ PIX == 1, ALPHA_SEL == 0)
If WINEN_F is enabled and BLD_PIX is disabled, then AR is controlled by ALPHA_SEL ALPHA0. AEN bit
information is not used anymore.
1 0BDISPLAY CONTROLLER
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