Allwinner A20 - Page 541

A20 User Manual (Revision 1.2) Copyright © 2013 Allwinner Technology Co., Ltd. All Rights Reserved. Page 541 / 812
Offset:
Layer0: 0x890
Layer1: 0x894
Layer2: 0x898
Layer3: 0x89C
Register Name: DEBE_ATTCTL_REG0
Bit
Read/W
rite
Default/
Hex
Description
The rule is: 11>10>01>00
When more than 2 layers are enabled, the priority value of each
layer must be different, soft designer must keep the condition.
If more than 1 layer selects the same pipe, in the overlapping
area, only the pixel of highest priority layer can pass the pipe to
blender1.
If both 2 pipes are selected by layers, in the overlapping area,
the alpha value will use the alpha value of higher priority layer in
the blender1.
9:5
/
/
/
4
R/W
UDF
LAY_VDOSEL
Video channel selection control
0:select video channel 0 (FE0)
1:select video channel 1 (FE1)
The selection setting is only valid when Layer video channel
selection is enabled.
3
/
/
/
2
R/W
UDF
LAY_YUVEN
YUV channel selection
0: disable
1: enable
Setting 2 or more layers YUV channel mode is illegal,
programmer should confirm it.
1
R/W
UDF
LAY_VDOEN
Layer video channel selection enable control
0: disable
1: enable