DVI makes use of
Transition-Minimized
Differential Signaling (TMDS)
wherein eight bits of video data
are converted to a 10-bit
transition-minimized,
DC-balanced value. This value
is then serialized and sent to
the receiver where the data is
de-serialized and converted back
to eight bits.
The three TMDS signals needed
for RGB make up one TMDS link.
A DVI connector can carry up to
two TMDS links providing for
better resolutions and timing
requirements. Single TMDS
link DVI cables can support
resolutions and timings that use
a video clock rate of about
25-165 MHz.
The following resolutions and
timings are supported by a
single link DVI cable:
- SXGA resolution (1280 x 1024) with 85-Hz refresh rate
- UXGA resolution (1600 x 1200) with 60-Hz refresh rate
- SDTV resolutions of 480i, 480p, 576i and 576p
- HDTV resolutions of 720p and 1080i
Video clock rates of 165-330 MHz on the other hand, are supported only by dual TMDS link DVI cables. With dual link DVI cables, however, each TMDS link operates at only one-half the frequency of single link DVI. So the clock and bandwidth is shared by these two links.