Serial Digital Video Out

Serial Digital Video Out (SDVO) is a proprietary Intel technology introduced with their 9xx-series of motherboard chipsets.

SDVO makes it possible to use a 16-lane PCI express slot to add additional video signalling interfaces such as VGA and DVI monitor outputs, SDTV and HDTV television outputs, or TV tuner inputs to a system board containing an integrated Intel 9xx-series graphics processor.

SDVO adaptor cards are variously designated as ADD2 (advanced digital display, second generation) or the more feature-rich MEC (media expansion card). MEC is sometimes designated as ADD2+ in Intel documents.

Intel often refers to SDVO as Serial DVO to distinguish it from other forms of digital video out associated with prior product generations, such as the AGP implementation of DVO and older AGP-style ADD expansion cards which are not SDVO compatible.

Proprietary status

Intel's non-standard extension of the PCI express interface is subject to a patent application Mapping SDVO functions from PCI express interface (United States Application 20050172037) filed on 12 December 2003.

ADD2

Beta-adducin is a protein that in humans is encoded by the ADD2 gene.

Function

Adducins are heteromeric proteins composed of different subunits referred to as adducin alpha, beta and gamma. The three subunits are encoded by distinct genes and belong to a family of membrane skeletal proteins involved in the assembly of spectrin-actin network in erythrocytes and at sites of cell-cell contact in epithelial tissues.

While adducins alpha and gamma are ubiquitously expressed, the expression of adducin beta is restricted to brain and hematopoietic tissues. Adducin, originally purified from human erythrocytes, was found to be a heterodimer of adducins alpha and beta. Polymorphisms resulting in amino acid substitutions in these two subunits have been associated with the regulation of blood pressure in an animal model of hypertension. Heterodimers consisting of alpha and gamma subunits have also been described. Structurally, each subunit is composed of two distinct domains.

The amino-terminal region is protease resistant and globular in shape, while the carboxy-terminal region is protease sensitive. The latter contains multiple phosphorylation sites for protein kinase C, the binding site for calmodulin, and is required for association with spectrin and actin. Various adducin beta mRNAs, alternatively spliced at 3'end and/or internally spliced and encoding different isoforms, have been described. The functions of all the different isoforms are not known.