Intel 815 Manuel D’Utilisation
Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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15.4.1.6.
OBUF_1V—Overlay Buffer 1 V Pointer Register
Memory Address Offset:
14h (R/W)
On-chip Reg. Mem Addr Offset:
30114h (RO; debug path)
Default Value:
00h
Access:
see address offset above
Size:
32 bits
31 26
25
0
Reserved
Overlay Buffer 1 V Pointer
Bit Description
31:26
Reserved.
25:0
Overlay Buffer 1 V Pointer. This register is used for YUV Planar Modes only. It points to the start of
the V addresses in the interleaved UV formats (byte address).
the V addresses in the interleaved UV formats (byte address).
15.4.2. Overlay Stride Registers
These values represent the width of the buffer that contains the overlay data. This is independent of the
actual width displayed and is used to determine the line-to-line increment of the overlay buffer. In two
line buffer mode, there is only room for 180 quadwords per scan line. If the source address is not
quadword aligned, then for formats: YUV4:2:0, YUV4:2:2, and RGB, the source must be less then 720
pixels. The stride must be quadword aligned.
actual width displayed and is used to determine the line-to-line increment of the overlay buffer. In two
line buffer mode, there is only room for 180 quadwords per scan line. If the source address is not
quadword aligned, then for formats: YUV4:2:0, YUV4:2:2, and RGB, the source must be less then 720
pixels. The stride must be quadword aligned.
15.4.2.1.
OV0STRIDE—Overlay 0 Stride Register
Memory Address Offset:
18h (R/W)
On-chip Reg. Mem Addr Offset:
30118h (RO; debug path)
Default Value:
00h
Access:
see address offset above
Size:
32 bits
31
26 28
16 15
13 12
0
Reserved
Overlay 0 UV planar
Buffer Stride
Reserved
Overlay 0 Y planar or
YUV/RGB Buffer Stride
Bit Description
31:29
Reserved.
28:16
Overlay 0 UV planar Buffer Stride. Only used for YUV Planar formats and gives the U or V buffer
stride in bytes. This is a two’s complement number and is negative during Y mirroring. The low-order
three bits are always zero forcing a QWord alignment. The range is ±4 KB.
stride in bytes. This is a two’s complement number and is negative during Y mirroring. The low-order
three bits are always zero forcing a QWord alignment. The range is ±4 KB.
15:13
Reserved.
12:0
Overlay 0 Y planar or YUV/RGB Buffer Stride. Buffer (Y planar or YUV/RGB packed ) stride in bytes.
This is a two’s complement number and is negative during Y mirroring. The low-order three bits are
always zero. The range is ±4 KB.
This is a two’s complement number and is negative during Y mirroring. The low-order three bits are
always zero. The range is ±4 KB.