39.6.4.10 18 bpp Unpacked Memory Mapping with Transparency Bit, RGB 6:6:6

Table 39-17. 18 bpp Unpacked Memory Mapping, Little Endian Organization
Mem address 0x3 0x2 0x1 0x0
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Pixel 18 bpp R0[5:0] G0[5:0] B0[5:0]