PXD20RM Datasheet, PDF (538/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Table 12-66. Data layout for 2 bpp
Address
offset
[0:7]
[8:15]
0x00 pixel3-pixel0 pixel7-pixel4
0x08
pixel35-
pixel32
pixel39-
pixel36
[16:23]
pixel11-
pixel8
pixel43-
pixel40
[24:31]
pixel15-
pixel12
pixel47-
pixel44
[0:7]
pixel19-
pixel16
pixel51-
pixel48
[8:15]
pixel23-
pixel20
pixel55-
pixel52
[16:23]
pixel27-
pixel24
pixel59-
pixel56
[24:31]
pixel31-
pixel28
pixel63-
pixel60
Table 12-67. Data layout for 1 bpp
Address
offset
[0:7]
[8:15]
[16:23] [24:31]
[0:7]
[8:15]
[16:23] [24:31]
0x00
0x08
pixel7-pixe pixel15-pix pixel23-pix pixel31-pix pixel39-pix pixel47-pix pixel55-pix pixel63-pix
l0
el8
el16
el24
el32
el40
el48
el56
pixel71-pix pixel79-pix pixel87-pix pixel95-pix pixel103-pi pixel11-pix pixel119-pi pixel127-pi
el64
el72
el80
el88
xel96
el104
xel112
xel120
The DCULite includes a flag that indicates when it has completed fetching graphics from memory for the
current frame refresh. If required, this flag (DMA_TRANS_FINISH in the INT_STATUS register) can be
used to determine when changes can be made to the source graphic content.
12.4.4.5 Alpha and Chroma-key blending
The blending configuration of each layer is defined by the BB, AB, and TRANS bit fields in register 4 in
the control descriptor for the layer (CTRLDESCLn_4, where n is the layer number). The pixels affected
by the blending configuration can be further selected by registers 5 and 6 in the control descriptor
(CTRLDESCLn_4 and CTRLDESCLn_5). Depending on the priority and placement of the layer (see
Section 12.4.4.1, Blending priority of layers), these bit fields and registers define how pixels from different
layers are blended together.
The AB and BB bit fields define whether blending is active and whether the whole graphic or a selected
portion is blended. Registers 5 and 6 define the range of RGB colors that define the selected pixels. The
TRANS bit field defines the transparency of the selected pixels.
The BB bit field defines whether the whole graphic, or only certain pixels, should be blended. When this
bit is set, pixels that have an RGB value that falls into the range defined by registers 5 and 6 are considered
to be selected and treated differently to the non-selected pixels in the graphic. This is a process known as
chroma-keying since it is the color of the pixel that defines the selection. The selected pixels must be
within the range defined by each color component of registers 5 and 6. See Table 12-68 for examples of
pixels that are selected and not selected when the given range is defined as 0x0080C0 to 0x0FB0FF.
Table 12-68. Example of how chroma-key range selects pixels
Source pixel
0x000000
Red 00–0F
P
Green 80–B0
X
Blue C0–FF
X
Comment
Not selected
12-76
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor