RIVA128ZX Datasheet, PDF (57/85 Pages) STMicroelectronics – 128-BIT 3D MULTIMEDIA ACCELERATOR

128-BIT 3D MULTIMEDIA ACCELERATOR
RIVA128ZX
11 DISPLAY INTERFACE
11.1 PALETTE-DAC
The Palette-DAC integrated into the RIVA128ZX
supports a traditional pixel pipeline with the follow-
ing enhancements:
• Support for 10:10:10, 8:8:8, 5:6:5 and 5:5:5 di-
rect color pixel modes
• Support for dynamic gamma correction on a
pixel by pixel basis
• Support for mixed indexed color and direct col-
or pixels
• 256 x 24 LUT for 8-bit indexed modes
• High quality video overlay
- Accepts interlaced video fields allowing a re-
duction in memory buffering requirements while
incorporating temporal averaging
- Line buffer for horizontal and vertical interpola-
tion of video streams up to square pixel PAL
resolution
- 3x2 multitap interpolating filter with image
sharpening
- Color key in all color pixel modes
- High quality YUV to RGB conversion with
chrominance control.
11.2 PIXEL MODES SUPPORTED
8-bit indexed color
In the 8-bit indexed color each 32-bit word contains four 8-bit indexed color pixels, each comprising bits
b[7:0] as shown below.
Pixel formats (FBD[31:0])
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Pixel 3
Pixel 2
Pixel 1
Pixel 0
b7 b6 b5 b4 b3 b2 b1 b0 b7 b6 b5 b4 b3 b2 b1 b0 b7 b6 b5 b4 b3 b2 b1 b0 b7 b6 b5 b4 b3 b2 b1 b0
NOTE
1 This 32-bit representation can be extended to 64-bit and 128-bit widths by duplicating the 32-bit word in little-endian format.
16-bit direct color modes (5:6:5 direct and 5:5:5 with and without gamma correction)
In 5:5:5 color modes bit 15 of each pixel can be enabled to select whether pixel data bypasses the LUT to
feed the DACs directly, or indirectly, through the LUT, to allow gamma correction to be applied. If not en-
abled then the bypass mode will always be selected, and the LUT powered down. The 16-bit modes in-
clude a 5:6:5 format which always bypasses the LUT.
Pixel formats (FBD[31:0])
5:6:5
mode
Pixel 1
Pixel 0
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 Red gamma Green gamma Blue gamma 0 Red gamma Green gamma Blue gamma
0 1 Red bypass Green bypass Blue bypass 1 Red bypass Green bypass Blue bypass
1 Red bypass
Green bypass
Blue bypass Red bypass
Green bypass
Blue bypass
NOTE
1 This 32-bit representation can be extended to 64-bit and 128-bit widths by duplicating the 32-bit word in little-endian for-
mat.
32-bit direct color (8:8:8 with gamma correction or 10:10:10 direct)
In 32-bit color mode bit 31 of each pixel selects whether pixel data bypasses the LUT, to feed the DACs
directly or indirectly, through the LUT, to allow gamma correction to be applied. In the table below the Red,
Green and Blue bypass bits are shown individually as R[9:0], G[9:0], and B[9:0] because, in the bypass
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