L64105 LSI Logic Corporation, L64105 Datasheet - Page 323

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

9.9.2.7 OSD Requirements
9.9.3 External OSD
The following list of requirements must be met to program OSD areas:
The Video Interface has provisions for interfacing with an external OSD
Controller such as a character generator integrated circuit. To operate in
External Mode, the host must first load the color palette information into
the color look-up table (CLUT) in on-chip RAM. The bitmap data is fed
in on the EXT_OSD[3:0] pins of the L64105.
On-Screen Display
The OSD header MUST be word aligned in SDRAM.
The OSD header should NOT include a row or column number that
is out of range of the current display parameters, EXCEPT in the
Termination Header.
The row end address MUST be greater than the row start address,
EXCEPT in the Termination Header.
The column end address MUST be greater than the column start
address.
OSD areas MUST NOT overlap each other in any way or be
programmed on the same line or lines.
OSD areas should be ordered top to bottom in the display list.
The OSDA pointers MUST point to valid OSD headers.
In Linked-List OSD mode, the width of an OSD area must be a
multiple of 32 pixels in 2 bits/pixel mode, 16 pixels in 4 bits/pixel
mode, or 8 pixels in 8 bits/pixel mode.
In Contiguous OSD mode, the total number of pixels in an OSD area
must be a multiple of 32 pixels in 2 bits/pixel mode, 16 pixels in
4 bits/pixel mode, or 8 pixels in 8 bits/pixel mode.
The number of bits in the bitmap should not exceed the available
memory space.
The colors programmed into the color palette should be legal ITU-R
BT.601 colors.
The OSD image width must not exceed 720 pixels.
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