Datasheet
SAM9261 [DATASHEET]
Atmel-6062O-ATARM-SAM9261-Datasheet_21-Jun-16
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37.5.2.5 Palette
This block is used to generate the pixel gray or color information in palletized configurations. The different modes
with the palletized/non-palletized configuration can be found in Table 37-5. In these modes, 1, 2, 4 or 8 input bits
index an entry in the lookup table. The corresponding entry in the lookup table contains the color or gray shade
information for the pixel.
The lookup table can be accessed by the host in R/W mode to allow the host to program and check the values
stored in the palette. It is mapped in the LCD controller configuration memory map. The LUT is mapped as 16-bit
half-words aligned at word boundaries, only word write access is allowed (the 16 MSB of the bus are not used).
For the detailed memory map, see Table 37-12 on page 644.
The lookup table contains 256 16-bit wide entries. The 256 entries are chosen by the programmer from the 2
16
possible combinations.
For the structure of each LUT entry, see Table 37-6.
In STN Monochrome, only the four most significant bits of the red value are used (16 gray shades). In STN Color,
only the four most significant bits of the blue, green and red value are used (4096 colors).
In TFT mode, all the bits in the blue, green and red values are used (32768 colors). In this mode, there is also a
common intensity bit that can be used to double the possible colors. This bit is the least significant bit of each color
component in the LCDD interface (LCDD[18], LCDD[10], LCDD[2]). The LCDD unused bits are tied to 0 when TFT
palletized configurations are used (LCDD[17:16], LCDD[9:8], LCDD[1:0]).
Table 37-5. Palette Configurations
Configuration
PaletteDISTYPE PIXELSIZE
TFT 1, 2, 4, 8 Palletized
TFT 16, 24 Non-palletized
STN Mono 1, 2 Palletized
STN Mono 4 Non-palletized
STN Color 1, 2, 4, 8 Palletized
STN Color 16 Non-palletized
Table 37-6. Lookup Table Structure in the Memory
Address Data Output [15:0]
00 Intensity_bit_0 Blue_value_0[4:0] Green_value_0[4:0] Red_value_0[4:0]
01 Intensity_bit_1 Blue_value_1[4:0] Green_value_1[4:0] Red_value_1[4:0]
...
FE Intensity_bit_254 Blue_value_254[4:0] Green_value_254[4:0] Red_value_254[4:0]
FF Intensity_bit_255 Blue_value_255[4:0] Green_value_255[4:0] Red_value_255[4:0]