Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

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15.4.10. Overlay Configuration Registers

There is only 1 Overlay Configuration register which controls both overlay streams. It is read from memory with Overlay 0 register loads during Vertical Blank.

15.4.10.1. OV0CONF—Overlay Configuration Register

Memory Address Offset:

 

64h (R/W)

 

 

 

 

 

On-chip Reg. Mem Addr Offset:

30164h (RO; debug path)

 

 

Default Value:

 

00h

 

 

 

 

 

Access:

 

 

 

 

 

see address offset above

 

 

Size:

 

 

 

 

 

32 bits

 

 

 

 

 

31

 

 

 

 

 

 

 

 

 

8

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

6

 

5

4

3

1

0

 

 

 

Reserved

 

Cr Cb

 

Reserved

YUV Conv

 

 

Reserved

Line Buf

 

 

 

 

 

 

Rdjust En

 

 

En

 

 

 

Conf

 

 

 

 

 

 

(Reserved)

 

 

(Reserved)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bit

 

 

 

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

 

 

 

 

31:7

Reserved.

 

 

 

 

 

 

 

 

 

 

 

 

 

6

Cr Cb Readjust Enable. (Reserved Field in Intel® 810 Chipset. Reserved for future

 

 

 

 

 

implementations.)

 

 

 

 

 

 

 

 

 

 

0

= Disable Cr Cb Readjust

 

 

 

 

 

 

 

 

 

1

= Enable Cr Cb Readjust (TV-Out mode = convert back to U,V = excess 128 and Y=Y+16)

 

 

 

 

 

 

 

 

 

 

 

 

5

Reserved.

 

 

 

 

 

 

 

 

 

 

 

 

4

YUV Conversion Enable. (Reserved for future implementations.) The conversion disabled setting

 

 

 

 

should only be used when the overlay data is being directed out to the video side port.

 

 

 

 

 

0

= Enable YUV Conversion

 

 

 

 

 

 

 

 

 

1

= Disable YUV Conversion (TV-Out: YUV 4:4:4) mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3:1

Reserved.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

Line Buffer Configuration. Sets the line buffer configuration:

 

 

 

 

 

 

0

= 2 720 pixel line buffers

 

 

 

 

 

 

 

 

 

1

= 1 1440 pixel line buffer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Image 293
Intel 815 manual Overlay Configuration Registers, 15.4.10.1. OV0CONF-Overlay Configuration Register