Nxp semiconductors – NXP Semiconductors LPC24XX UM10237 User Manual
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UM10237_4
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 04 — 26 August 2009
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NXP Semiconductors
UM10237
Chapter 12: LPC24XX LCD controller
Pixel data values can be written and verified through the AHB slave interface. For
information on the supported colors, refer to the section on the related panel type earlier in
this chapter.
The palette RAM is a dual port RAM with independent controls and addresses for each
port. Port1 is used as a read/write port and is connected to the AHB slave interface. The
palette entries can be written and verified through this port. Port2 is used as a read-only
port and is connected to the unpacker and gray scaler. For color modes of less than 16
bpp, the palette enables each pixel value to be mapped to a 16-bit color:
•
For TFT displays, the 16-bit value is passed directly to the pixel serializer.
•
For STN displays, the 16-bit value is first converted by the gray scaler.
shows the bit representation of the palette data. The palette 16-bit output
uses the TFT 1:5:5:5 data format. In 16 and 24 bpp TFT mode, the palette is bypassed
and the output of the pixel serializer is used as the TFT panel data.
The red and blue pixel data can be swapped to support BGR data format using a control
register bit (bit 8 = BGR). See the LCD_CTRL register description for more information.
shows the bit representation of the palette data for the STN color modes.
Table 250. Palette data storage for TFT modes.
Bit(s)
Name
(RGB format)
Description
(RGB format)
Name
(BGR format)
Description
(BGR format)
31
I
Intensity / unused
I
Intensity / unused
30:26
B[4:0]
Blue palette data
R[4:0]
Red palette data
25:21
G[4:0]
Green palette data
G[4:0]
Green palette data
20:16
R[4:0]
Red palette data
B[4:0]
Blue palette data
15
I
Intensity / unused
I
Intensity / unused
14:10
B[4:0]
Blue palette data
R[4:0]
Red palette data
9:5
G[4:0]
Green palette data
G[4:0]
Green palette data
4:0
R[4:0]
Red palette data
B[4:0]
Blue palette data
Table 251. Palette data storage for STN color modes.
Bit(s)
Name
(RGB format)
Description
(RGB format)
Name
(BGR format)
Description
(BGR format)
31
-
Unused
-
Unused
30:27
B[3:0]
Blue palette data
R[3:0]
Red palette data
26
-
Unused
-
Unused
25:22
G[3:0]
Green palette data
G[3:0]
Green palette data
21
-
Unused
-
Unused
20:17
R[3:0]
Red palette data
B[3:0]
Blue palette data
16
-
Unused
-
Unused
15
I
Unused
I
Unused
14:11
B[4:1]
Blue palette data
R[4:1]
Red palette data
10
B[0]
Unused
R[0]
Unused
9:6
G[4:1]
Green palette data
G[4:1]
Green palette data