W9970CF Datasheet, PDF (5/6 Pages) Winbond – VIDEO GRAPHICS CONTROLLER

W9970CF
is the primary stream pixel data and Ps is the
secondary stream pixel data.
Overlay Control
The overlay controller provides control for overlaying
of four input sources: the primary stream (normally the
graphics data), secondary stream, blending stream,
and FC/VAFC pass-through data stream. When the
hardware cursor is active, it is overlaid on top of all
stream images. The W9970CF supports a range of
advanced forms of keying including window key, color
key, chroma key, software key (1-bit alpha overlaying
in RGB 1:5:5:5 format), external key (FC/VAFC
only), and a logic combination of these keys.
Dual Video Windows
Two video windows may be displayed on the monitor
simultaneously. This makes W9970CF highly suitable
for video conferencing applications. If the two video
windows are placed at different scan lines, they can be
scaled separately with different factors.
16
Host Data
32
CODEC
FIFO
8 HD Bus
8/16 YUV Bus
Cropping
&
Filtering
Multimedia
Video
Interface
CSC
2-D Bilinear
Interpolation
FC/VAFC
8/16
Primary
24
Stream
H/W Cursor
8
Overlay
1
24
RGB 8.8.8
256X18
LUT
Down-
Scaling
Line Buffer
Capture ^32/64
FIFO
DRAM
Controller
SS
32/64 _Secondary
FIFO
Stream
MSW
MUX
Blending
&
24
Overlay 2
24
2X
DAC
Figure 3. Video Accelerator Block Diagram
Preliminary
-5-
March 1996