Texas Instruments Development Kit for TM4C129x,Tiva™ ARM® Cortex™ -M4 Microcontroller DK-TM4C129X DK-TM4C129X Datenbogen
Produktcode
DK-TM4C129X
The LCD palette RAM uses a 12-bit output code such that there is a possibility of 4096 color options
to choose from. Depending on the bpp frame storage of palette RAM, two, four, 16, or 256 palette
colors can be stored in the palette RAM.
to choose from. Depending on the bpp frame storage of palette RAM, two, four, 16, or 256 palette
colors can be stored in the palette RAM.
26.3.5.1
Palette RAM Structure for 1, 2, and 4 Bits Per Pixel
When palette RAM is enabled for 1, 2, and 4 bpp frame storage, the palette buffer is 16 word entries,
where the upper half of the word is unused. The first entry of the palette RAM contains the encoding
for the palette type (1, 2, 3, 6, or 12/16/24) of the stored picture on bits [14:12] , as well as the first
input code for one palette entry (bits [11:0]). Subsequent entries only contain the input codes for
next palette entries. Figure 26-4 on page 1858 shows the frame buffer structure.
where the upper half of the word is unused. The first entry of the palette RAM contains the encoding
for the palette type (1, 2, 3, 6, or 12/16/24) of the stored picture on bits [14:12] , as well as the first
input code for one palette entry (bits [11:0]). Subsequent entries only contain the input codes for
next palette entries. Figure 26-4 on page 1858 shows the frame buffer structure.
Figure 26-4. Palette RAM Structure for 1, 2, and 4 Bits Per Pixel
Palette Entry 1
Palette Entry 0
Palette Entry 3
Palette Entry 2
Palette Entry 5
Palette Entry 4
Palette Entry 7
Palette Entry 6
Palette Entry 9
Palette Entry 8
Palette Entry 11
Palette Entry 10
Palette Entry 13
Palette Entry 12
Palette Entry 15
Palette Entry 14
3
0
3
0
7
4
7
4
11
8
11
8
14
12
14
12
15
15
Blue
Green
Red
Blue
Green
Red
000
Type
0
0
31
16
15
0
Picture Data
8 Words
First Entry
Subsequent
Entries
Note that for 1 bpp source pictures, the first two palette entries are valid; for 2 bpp sources, the first
four palette entry sources are valid; for 4 bpp, all 16 palette entries are valid. Even if the palette
entries are not valid for a particular type, there is a fixed number of 8 words reserved for the palette
RAM.
four palette entry sources are valid; for 4 bpp, all 16 palette entries are valid. Even if the palette
entries are not valid for a particular type, there is a fixed number of 8 words reserved for the palette
RAM.
The first palette entry represents the RGB value for the source pixel encoded as 0x0. The second
palette entry represents the RBG values for the source pixel encoded as 0x1, and so on, such that
the sixteenth palette entry is used to represent the RGB values for a pixel encoded as 0xF.
palette entry represents the RBG values for the source pixel encoded as 0x1, and so on, such that
the sixteenth palette entry is used to represent the RGB values for a pixel encoded as 0xF.
Source data encoded as 12, 16, or 24 bpp do not use the palette RAM since the encoded data
already represents the actual RGB values. However, 16 palette RAM entries still precede the picture
data in this case and the first palette entry must still define the bpp in bits [14:12]. The type field
encoding is defined below in Table 26-6 on page 1859
already represents the actual RGB values. However, 16 palette RAM entries still precede the picture
data in this case and the first palette entry must still define the bpp in bits [14:12]. The type field
encoding is defined below in Table 26-6 on page 1859
December 13, 2013
1858
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