Samsung S3C2451X User Manual page 562

LCD CONTROLLER
WINDOW BLENDING
OVERVIEW
The main function of the VPRCS module is window blending. LCD controller has 2-window layers and the detail is
described below. As an example of application, System can use win0 as an OS window, full TV screen window or
etc. This feature enhances the system performance by reducing the data rate of total system.
Total 2 windows
Window 0 (base)
Window 1 (overlay) : RGB with palette
Overlay Priority
Win 1 > Win 0
Blending equation
WinOut(R) = Win0(R) x (1-AR) + Win1(R) x AR
WinOut(G) = Win0(G) x (1-AG) + Win1(G) x AG
WinOut(B) = Win0(B) x (1-AB) + Win1(B) x AB
Where,
AR = Win1's Red blending factor(ALPHA0_R/16 or ALPHA1_R/16 or DATA[27:24]/16, AR range is 0~1)
AG = Win1's Green blending factor(ALPHA0_G/16 or ALPHA1_G/16 or DATA[27:24]/16, AG range is 0~1)
AB = Win1's Blue blending factor(ALPHA0_B/16 or ALPHA1_B/16 or DATA[27:24]/16, AB range is 0~1)
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
22-22
Specifications and information herein are subject to change without notice.
: RGB with palette
Figure 22-5. Blending Operations
S3C2451X RISC MICROPROCESSOR