Table 90. Pixel Data Mapping Versus Color Format; Figure 83. Layer Window Programmable Parameters - ST STM32F405 Reference Manual

RM0090
Pixel input Format
The programmable pixel format is used for the data stored in the frame buffer of a layer.
Up to 8 input pixel formats can be configured for every layer through the LTDC_LxPFCR
register
The pixel data is read from the frame buffer and then transformed to the internal 8888
(ARGB) format as follows:
•
Components which have a width of less than 8 bits get expanded to 8 bits by bit
replication. The selected bit range is concatenated multiple times until it is longer than
8 bits. Of the resulting vector, the 8 MSB bits are chosen. Example: 5 bits of an
RGB565 red channel become (bit positions): 43210432 (the 3 LSBs are filled with the 3
MSBs of the 5 bits)
The figure below describes the pixel data mapping depending on the selected format.
A
B
G
R [4:0] G
x+1

Figure 83. Layer window programmable parameters:

WVSTPOS bits in
LTDC_LxWVPCR
WHSTPOS bits in
LTDC_LxWHPCR

Table 90. Pixel Data mapping versus Color Format

@+3
A [7:0]
x
@+7
[7:0]
x+1
@+3
[7:0]
x+1
@+7
[7:0]
x+2
@+3
[5:3] G
x+1 x+1
Window
WHSPPOS bits in
LTDC_LxWHPCR
ARGB8888
@+2
R [7:0]
x
@+6
R [7:0]
x+1
RGB888
@+2
R [7:0]
x
@+6
B [7:0]
x+2
RGB565
@+2
[2:0] B [4:0] R
x+1
RM0090 Rev 18
LCD-TFT controller (LTDC)
Active data area
WVSPPOS bits in
LTDC_LxWVPCR
@+1
G [7:0]
x
@+5
G [7:0]
x+1
@+1
G [7:0]
x
@+5
R [7:0]
x+1
@+1
[4:0] G [5:3] G
x x
MSv19676V3
@
B [7:0]
x
@+4
B [7:0]
x+1
@
B [7:0]
x
@+4
G [7:0]
x+1
@
[2:0] B [4:0]
x x
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