Allwinner A20 - Page 543

A20 User Manual (Revision 1.2) Copyright © 2013 Allwinner Technology Co., Ltd. All Rights Reserved. Page 543 / 812
Offset:
Layer0: 0x8A0
Layer1: 0x8A4
Layer2: 0x8A8
Layer3: 0x8AC
Register Name: DEBE_ATTCTL_REG1
Bit
Read/W
rite
Default/
Hex
Description
11: Reserved
13:12
R/W
UDF
LAY_WSCAFCT
Setting the internal frame buffer scaling factor, only valid in
internal frame buffer mode
SW
Width scale factor
00: no scaling
01: *2
10: *4
11: Reserved
11:8
R/W
UDF
LAY_FBFMT
Frame buffer format
Normal mode data format
0000: mono 1-bpp
0001: mono 2-bpp
0010: mono 4-bpp
0011: mono 8-bpp
0100: color 16-bpp (R:6/G:5/B:5)
0101: color 16-bpp (R:5/G:6/B:5)
0110: color 16-bpp (R:5/G:5/B:6)
0111: color 16-bpp (Alpha:1/R:5/G:5/B:5)
1000: color 16-bpp (R:5/G:5/B:5/Alpha:1)
1001: color 24-bpp (Padding:8/R:8/G:8/B:8)
1010: color 32-bpp (Alpha:8/R:8/G:8/B:8)
1011: color 24-bpp (R:8/G:8/B:8)
1100: color 16-bpp (Alpha:4/R:4/G:4/B:4)
Other: Reserved
Palette Mode data format
In palette mode, the data of external frame buffer is regarded as
pattern.
0000: 1-bpp
0001: 2-bpp
0010: 4-bpp