L64105 LSI Logic Corporation, L64105 Datasheet - Page 298

• Manufacturer Part Number: L64105
• Description: Mpeg-2 Audio/video Decoder
• Manufacturer: LSI Logic Corporation

Figure 9.2
VSYNC
9-6
Line
CNT
Display Areas Example
H_CNT
SAV
The Display Controller includes counters for counting the horizontal offset
and the vertical offset from the new field timing. The horizontal offset is
measured in device clocks from the HS, while the vertical offset is
measured as a line offset from the new field timing. The Display
Controller uses these counters to determine the location of the various
display areas. The host programs row and column start and end values
in registers to define the location of the main display area. The start
values determine the position of the upper left corners of the area while
the end values set the position of the lower right corner. The location of
the main display area is controlled by Registers 297–302
The main display area is intended for the display of either a decoded
video sequence or a separate still image. This section focuses on the
display of decoded video sequences; still image display features are
covered later. As described earlier, the host must define the area by
programming the start and end points of the area. The data for the main
display area is both horizontally scaled and vertically filtered based on
the programmed display mode. Since the image may be horizontally
scaled, the number of pixels to be read from the frame store may not be
the same as the number of pixels required for the displayed image.
Video Interface
Active Display Area
Main
OSD
EAV
(page
HSYNC
4-70).