R,G,B data + clock and display data channel (TDMS)
Width
36 bit (maximum)
Bandwidth
16 Gbit/s
Pins
26
Pin out
Pin 1
Supply voltage for data link circutry
VDD_UDL
Pin 2
Supply voltage for data link circutry
VDD_UDL
Pin 3
Supply voltage for data link circutry
VDD_UDL
Pin 4
Supply voltage for data link circutry
VDD_UDL
Pin 5
Supply return for control and data link power
VSS
Pin 6
Supply return for control and data link power
VSS
Pin 7
Supply return for control and data link power
VSS
Pin 8
Supply return for control and data link power
VSS
Pin 9
Positive side of UDI lane 0 data (userd for x1 and x3 lane widths)
UDI_Data0+
Pin 10
Negative side of UDI lane 0 data (userd for x1 and x3 lane widths)
UDI_Data0-
Pin 11
Shield for UDI_Data0[-/-]
GND
Pin 12
Positive side of UDI lane 1 data (userd for x1 and x3 lane widths)
UDI_Data1+
Pin 13
Negative side of UDI lane 1 data (userd for x1 and x3 lane widths)
UDI_Data1-
Pin 14
Shield for for UDI_Data1[-/-]
Ground
Pin 15
Positive side of UDI lane 2 data (userd for x1 and x3 lane widths)
UDI_Data2+
Pin 16
Negative side of UDI lane 1 data (userd for x1 and x3 lane widths)
UDI_Data2-
Pin 17
Shield for for UDI_Data2[-/-]
GND
Pin 18
Reserved connector pin. No cable connection
(NC)
Pin 19
Reserved connector pin. No cable connection
(NC)
Pin 20
Reserved connector pin. No cable connection
(NC)
Pin 21
(Test Pin)
Pin 22
Ground return
GND
Pin 23
Supply voltage for control link signals
UDI_EPwr
Pin 24
UDI control link clock
UDI_CtrlClk
Pin 25
UDI Control link data
UDI_CtrlData
Pin 26
UDI link hot-plug detect
UDI_HPD
Unified Display Interface (UDI) is a digital video interface specification based on Digital Visual Interface. It is intended to be a lower-cost implementation while providing compatibility with existing High-Definition Multimedia Interface (HDMI) and DVI displays. Unlike HDMI, which is aimed at high-definition multimedia consumer electronics devices such as television monitors and DVD players, UDI is specifically targeted towards the needs of computer monitor and video card manufacturers.
Overview
UDI provides higher bandwidth than its predecessors (up to 16 Gbit/s in its first version, compared to 4.9 Gbit/s for HDMI 1.0) and incorporates a form of Digital Rights Management known as High-bandwidth Digital Content Protection. The connector has a single row of 26 contacts pitched 0.6 mm apart from each other, looking very similar to the USB plug which has a single row with only four contacts. Three of the 26 contacts will not be wired but are reserved for undetermined future upgrade possibilities. Transmit and receive plugs are slightly different, and a UDI cable will fit only one way. Bidirectional communication works at a much lower data rate than that available for the single direction video datastream. On December 202005, the UDI Special Interest Group (UDI SIG) was announced. They worked on determining the refined specifications and promoting the interface. Members include Silicon Image Inc., Apple Computer, LG, and NVIDIA. The specification was finalized in July 2006. The differences between UDI and HDMI will be kept to a minimum, as both specifications will be aligned for long-term compatibility. DisplayPort is a competing standard which is also under development. By CES 2007, Samsung and Intel have withdrawn from the UDI SIG, with Apple likely to follow suit. With those major players dropping support for UDI, the standard will unlikely be implemented in a widespread fashion, if at all, especially with the adoption of the competing DisplayPort as a VESA standard.
