JG82852GMSL7VP Datasheet, PDF (135/176 Pages) Intel Corporation – Intel® 852GM/852GMV Chipset Intel® 852GM/852GMV Chipset Hub (GMCH)

Functional Description
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5.4.5.
Planes and Engines
The GMCH display can be functionally delineated into Planes and Engines (Pipes and Ports). A plane
consists of rectangular shaped image that has characteristics such as source, size, position, method, and
format. These planes get attached to source surfaces, which are rectangular System Memory surfaces
with a similar set of characteristics. They are also associated with a particular destination pipe.
A pipe consists of a set of planes that will be combined and a timing generator. A port is the destination
for the result of the pipe. Therefore, planes are associated with pipes and pipes are associated with ports.
5.4.5.1. Dual Pipe Independent Display Functionality
The display consists of two display pipes, A and B. Pipes have a set of planes that are assigned to them
as sources. The analog display port may only use Pipe A or Pipe B, the DVO C port may use either Pipe
A or Pipe B, and the LFP LVDS interface may only use Pipe B. This limits the resolutions available on a
digital display when an analog CRT is active.
Table 28. Dual Display Usage Model (Intel 852GM/852GMV GMCH)
Display Pipe A
Display Pipe B
CRT
DVO C
CRT
DVO C
CRT/DVO C
LVDS
CRT
DVO C
LVDS
LVDS
5.4.6.
5.4.6.1.
5.4.6.2.
Hardware Cursor Plane
The GMCH supports two hardware cursors. The cursor plane is one of the simplest display planes. With
a few exceptions, has a fixed size of 64 x 64 and a fixed Z-order (top). In legacy modes, cursor can cause
the display data below it to be inverted. In the alpha blend mode, true color cursor data can be alpha
blended into the display stream. It can be assigned to either display pipe A or display pipe B and
dynamically flipped from one to the other when both are running.
Cursor Color Formats
Color data can be in an indexed format or a true color format. Indexed data uses the entries in the four-
entry cursor palette to convert the two-bit index to a true color format before being passed to the
blenders. The index can optionally specify that a cursor pixel be transparent or cause an inversion of the
pixel value below it or one of two colors from the cursor palette. Blending of YUV or RGB data is only
supported with planes that have data of the same format.
Popup Plane (Second Cursor)
The popup plane is used for control functions in mobile applications. Only the hardware cursor has a
higher Z-order precedence over the hardware icon. In standard modes (non-VGA) either cursor A or
cursor B can be used as a Popup Icon. For VGA modes, 32-bpp data format is not supported.
Intel^® 852GM/852GMV Chipset GMCH Datasheet
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