User's Manual

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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15.4.3.2. UV_VPH—UV Vertical Phase Register
Memory Address Offset: 20h (R/W)
On-chip Reg. Mem Addr Offset: 30120h (RO; debug path)
Default Value: 00h
Access: see address offset above
Size: 32 bits
31 20 19 16 15 4 3 0
UV Vertical Phase 1 Reserved UV Vertical Phase 0 Reserved
Bit Description
31:20 UV Vertical Phase 1. This fractional value is only used in YUV planar formats where the UV plane
may have a different vertical initial phase from the Y data. This field is used with Buffer 1 in frame
mode or Field 1 in field mode.
19:16 Reserved.
15:4 UV Vertical Phase 0. This fractional value is only used in YUV planar formats where the UV plane
may have a different vertical initial phase from the Y data. This field is used with Buffer 0 in frame
mode or Field 0 in field mode.
3:0 Reserved.
15.4.3.3. HORZ_PH—Horizontal Phase Register
Memory Address Offset: 24h (R/W)
On-chip Reg. Mem Addr Offset: 30124h (RO; debug path)
Default Value: 00h
Access: see address offset above
Size: 32 bits
31 20 19 16 15 4 3 0
UV Horizontal Phase Reserved Y/RGB Horizontal
Phase
Reserved
Bit Description
31:20 UV Horizontal Phase. Sets the initial horizontal phase for the UV data. Only used in YUV modes.
19:16 Reserved.
15:4 Y/RGB Horizontal Phase. Sets the initial horizontal phase for both buffers/fields. Unlike the vertical
initial phases, this does not change buffer to buffer or field to field. YUV modes use a separate initial
phase for Y and UV data. This value will either be the actual initial phase or the initial phase minus
one.
3:0 Reserved.