ADV8005 Hardware Reference Manual
UG-707
pvsp_vim_scal_type[1:0]
, Primary VSP Map,
Address 0xE8E5[7:6]
This signal is used to set the VIM scaling algorithm. For up-scaling, the proprietary ADI algorithm is recommended; whereas for down-
scaling, the sharp setting is recommended.
Function
pvsp_vim_scal_type[1:0]
Description
00
Proprietary ADI Algorithm
01
Sharp
10
Smooth
11 (default)
Bilinear
3.2.2.4.
Scaler Controls
The following register is used in the control of the VIM scaling function and should be tailored according to user requirements.
pvsp_vim_scal_overshoot_ctrl[11:0]
, Primary VSP Map,
Address 0xE8E9[7:0]; Address 0xE8EA[7:4]
This bit is used to control the overshoot in the scaling of input video. If set to a value larger than the default setting, more overshoot is
allowed.
Function
pvsp_vim_scal_overshoot_ct
rl[11:0]
Description
0x080 (default)
Default
3.2.2.5.
Pixel Packer
At the back end of the VIM, the pixel packer converts input video to word packets suitable for writing to external memory. Refer to
for more details on where the pixel packer is located in the hardware. Depending on the format of the input video, there are four different packing
formats:
•
12-bit 4:4:4 YCbCr
•
10-bit 4:4:4 YCbCr
•
12-bit 4:2:2 YCbCr
•
8-bit 4:2:2 YCbCr
There is a trade off in the number of bits that can be stored. A higher number of bits means the video stored will be stored at a higher quality,
however, this will reduce the available DDR2 memory bandwidth for other functions such as OSD read/write.
The data format can be set by the
register. This register can be set at any time, but it may take some time (not
more than 300 ms) to become valid. This delay is related to the
taking control of the memory format change to avoid the display of
garbage information. This information is important when calculating the field/frame buffer sizes, as explained in Section
pvsp_ex_mem_data_format[1:0]
, Primary VSP Map,
Address 0xE829[4:3]
This signal is used to set the data format in external memory.
Function
pvsp_ex_mem_data_format[
1:0]
Description
00 (default)
YCbCr-12b-10b-10b
01
YCbCr-8b-8b-8b
10
YCbCr-4:2:4-12b
11
YCbCr-4:2:2-8b
indicates the number of bytes required when storing a particular type of video data.
Table 23: Bytes per Pixel
pvsp_ex_mem_data_format
Format in Memory
Bytes per Pixel
0
12 bit 4:4:4 YCbCr
4
1
8 bit 4:4:4 YCbCr
3
2
12 bit 4:2:2 YCbCr
4
3
8 bit 4:2:2 YCbCr
2
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