Fujitsu MB86R02 Jade-D Hardware Manual page 377

MB86R02 'Jade-D' Hardware Manual V1.64
(2) Overlay mode
Image layer overlay is performed in two modes: simple priority mode and blend mode.
In the simple priority mode, processing is performed according to the transparent color defined for
each layer. When the color is a transparent color, the value of the lower layer is used as the image
value for the next stage; when the color is not a transparent color, the value of the layer is used as
the image value for the next stage.
D
When the L1 layer is in the YCbCr mode, transparent color checking is not performed for the L1
layer; processing is always performed assuming that transparent color is not used.
In the blend mode, the blend ratio "r" defined for each layer is specified using 8-bit tolerance and
the following operation is performed:
D
Blending is enabled for each layer by mode setting and a specific bit of the pixel is set to "1". For 8
bits/pixel, the MSB of RAM data enables blending; for 16 bits/pixel, the MSB of data of the relevant
layer enables blending; for 24 bits/pixel, the MSB of the word enables blending.
(3) Blend coefficient layer
In the normal blend mode, the blend coefficient is fixed for each layer. However, in the blend
coefficient layer mode, the L5 layer can be used as the blend coefficient layer. In this mode, the
blend coefficient can be specified for each pixel, providing gradation, for example. When using this
mode, set the L5 layer to 8 bits/pixel, widow display mode and extend overlay mode.
= D (when D does not match transparent color)
view new new
= D (when D matches transparent color)
lower new
×r + D × (1 – r)
= D
view new lower
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