301467-005 Datasheet, PDF (235/426 Pages) Intel Corporation – Express Chipset

Functional Description
R
12.6 Integrated Graphics Device (Intel^®
82915G/82915GV/82915GL/82910GL GMCH Only)
The GMCH provides a highly integrated graphics accelerator and chipset while allowing a
flexible integrated system graphics solution. Figure 12-2 shows a simplified block diagram of the
IGD in the GMCH.
Figure 12-2. Integrated Graphics Device Block Diagram
Video Engine
M
e
m
2D Engine
o
r
y
3D Engine
Display
Engine
Port
Mux
Control
DAC (Analog)
SDVOB (Digital)
SDVOC (Digital)
Gfx_Blk_Dia
High bandwidth access to data is provided through the graphics and system memory ports. The GMCH
can access graphics data located in system memory at 4.2 GB/s – 8.5 GB/s (depending on memory
configuration). The GMCH uses Intel’s Direct Memory Execution model to fetch textures from system
memory. The GMCH includes a cache controller to avoid frequent memory fetches of recently used
texture data.
The GMCH is able to drive an integrated DAC, and/or two SDVO ports (multiplexed with PCI
Express) capable of driving an ADD2 card. External SDVO devices are capable of driving a
standard progressive scan analog monitor with resolutions up to 2048x1536 @ 75 Hz. The SDVO
ports are capable of driving a variety of TV-Out, TMDS, and LVDS transmitters.
The GMCH’s Internal Graphics Device (IGD) contains several types of components. The major
components in the IGD are the engines, planes, pipes and ports. The GMCH has a 3D/2D
Instruction Processing unit to control the 3D and 2D engines. The IGD’s 3D and 2D engines are
fed with data through the memory controller. The outputs of the engines are surfaces sent to
memory, which are then retrieved and processed by the GMCH planes.
The GMCH contains a variety of planes (such as display, overlay, cursor and VGA). 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 that are rectangular memory
surfaces with a similar set of characteristics. They are also associated with a particular destination
pipe.
A pipe consists of a set of combined planes and a timing generator. The GMCH has two
independent display pipes, allowing for support of two independent display streams. A port is the
destination for the result of the pipe. The GMCH contains three display ports, 1 analog (DAC)
Datasheet
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