Epson S1D13706 - Bpp Color Depth; Figure 14-1: Byte-Swapping for 16 Bpp

Epson Research and Development
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Hardware Functional Specification S1D13706
Issue Date: 01/11/13 X31B-A-001-08
14.1.1 16 Bpp Color Depth
For 16 bpp color depth, the Display Data Byte Swap bit (REG[71h] bit 6) must be set
to 1.
Figure 14-1: Byte-swapping for 16 Bpp
For 16 bpp color depth, the MSB of the 16-bit pixel data is stored at the even system
memory address location and the LSB of the 16-bit pixel data is stored at the odd system
memory address location. Bus data byte swapping (automatic when the S1D13706 is
configured for Big-Endian) causes the 16-bit pixel data to be stored byte-swapped in the
S1D13706 display buffer. During display refresh this stored data must be byte-swapped
again before it is sent to the display.
aabb
ccdd
bb
bb aa
aa
015
0
15
D[15:8]
D[7:0]
* MSB is assumed to be associated with even address.
* LSB is assumed to be associated with odd address.
CPU Data
Byte Swap
System
Memory
Display
Buffer
(Big-Endian)
(Little-Endian)
0
0
System
Memory
Address
Display
Buffer
Address
cc
dd
dd
cc
MSB LSB
2
2
Display
Byte Swap
Data