82G33 datasheet(356/437 Pages) INTEL

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Functional Description

356

Datasheet

10.4

Intel® Serial Digital Video Output (SDVO) (Intel®

82Q35, 82Q33, 82G33 GMCH Only)

The SDVO signals on the GMCH are multiplexed with the PCI Express x16 port pins.

The Intel® SDVO Port is the second generation of digital video output from compliant

Intel® GMCHs. The electrical interface is based on the PCI Express interface, though

the protocol and timings are completely unique. Whereas PCI Express runs at a fixed

frequency, the frequency of the SDVO interface is dependant upon the active display

resolution and timing. The port can be dynamically configured in several modes to

support display configurations.

Essentially, an SDVO port will transmit display data in a high speed, serial format

across differential AC coupled signals. An SDVO port consists of a sideband differential

clock pair and a number of differential data pairs.

10.4.1

Intel® SDVO Capabilities

SDVO ports can support a variety of display types including LVDS, DVI, Analog CRT,

TV-Out and external CE type devices. The GMCH uses an external SDVO device to

translate from SDVO protocol and timings to the desired display format and timings.

The Internal Graphics Controller can have one or two SDVO ports multiplexed on the

x16 PCI Express interface. When an external x16 PCI Express graphics accelerator is

not in use, an ADD2 card may be plugged into the x16 connector or if a x16 slot is not

present, the SDVO(s) may be located ‘down’ on the motherboard to access the

multiplexed SDVO ports and provide a variety of digital display options.

The ADD2/Media Expansion card is designed to fit in a x16 PCI Express connector. The

ADD2/Media Expansion card can support one or two devices. If a single channel SDVO

device is used, it should be attached to the channel B SDVO pins. The ADD2 card can

support two separate SDVO devices when the interface is in Dual Independent or Dual

Simultaneous Standard modes. The Media Expansion card adds Video in capabilities.

The SDVO port defines a two-wire point-to-point communication path between the

SDVO device and GMCH. The SDVO control clock and data provide similar functionality

to I2C. However unlike I2C, this interface is intended to be point-to-point (from the

GMCH to the SDVO device) and requires the SDVO device to act as a switch and direct

traffic from the SDVO control bus to the appropriate receiver. Additionally, this control

bus will be able to run at faster speeds (up to 1 MHz) than a traditional I2C interface

would.

82G33 Datasheet(PDF) 356 Page - Intel Corporation