Dual-Link Dvi Signal - Lightware DA2DVI-DL User Manual

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9. Technologies
9.2. Dual-Link DVI signal
The Dual-Link DVI interface can operate in either Single-Link or Dual-
Link mode. The chosen mode depends on the pixel clock frequency of
the signal and it is selected by the hardware automatically. For pixel
clock frequencies lower than 165 MHz, Single-Link mode is selected.
For higher pixel clock frequencies (up to 330 MHz), Dual-Link mode is
selected. It is important to know that pixel clock frequency is not the
same as TMDS clock frequency when it comes to Dual-Link DVI.
The pixel clock frequency in Single-Link transmission is a 10th part of
the data rate. The maximum data rate of the Single-Link transmission is
1.65 Gbps per TMDS channel and the maximum pixel clock frequency
is 165 MHz. In this case the pixel clock frequency equals the TMDS
clock frequency. The pixel clock frequency in Dual-Link transmission
(when in Dual-Link mode) is a 5th part of the data rate. The maximum
data rate of Dual-Link transmission is still 1.65 Gbps per TMDS channel
but the maximum pixel clock frequency is 330 MHz. In this case the
pixel clock frequency is two times the TMDS clock frequency.
The DVI standard maximizes the data rate of the TMDS channels in
1.65 Gbps. Dual-Link DVI interface enables a higher resolution
compared to the Single-Link transmission by doubling the number of
wire pairs to transmit the video signal. In Single-Link cables 3 wire
pairs carry the color information (red, green and blue) and one wire
pair carries the clock signal (TMDS clock).
TMDS clock
Red
Green
PC or Mac
Blue
Video lines of the Single-Link interface
In Dual-Link cables, 6 wire pairs carry the color information next to the
TMDS clock signal. One color component is carried by two wire pairs,
where one wire pair carries the odd pixels and the other wire pair
carries the even pixels.
PC or Mac
Video lines of the Dual-Link interface
INFO: The colors of the wire pairs in the picture represent the color
information they carry and not the color of the actual wires inside
the cable.
Display
DA2DVI-DL – User's Manual
TMDS clock
Red even
Red odd
Green even
Green odd
Display
Blue even
Blue odd
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