10. Technologies
UMX-HDMI-140 series– User's Manual
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Applied firmware package: v1.3.0b5 | LDC software: v2.5.6b2
10.3.
Pixel Accurate Reclocking
Signal reclocking is an essential important procedure in digital signal transmission. After passing the
reclocking circuit, the signal becomes stable, jitter-free, and can be transmitted over more equipment like
processors, or event controllers. Without reclocking, sparkles, noise, and jaggies appear on the image.
Lightware’s sophisticated Pixel Accurate Reclocking technology fixes more problems than general TMDS
reclocking. It removes not only intra-pair skew but inter-pair skew as well. The Pixel Accurate Reclocking
circuit eliminates the following errors:
Intra-pair skew
Skew between the + and - wires within a differential wire pair (e.g. Data2- and Data2+). It’s caused by different
wire lengths or slightly different wire construction (impedance mismatch) in DVI cable. It results in jitter.
Inter-pair skew
Skew between two differential wire pairs in a cable. It is caused by different wire pair lengths or different
number of twists in the DVI cable. Too much inter-pair skew results color shift in the picture or sync loss.
Jitter
Signal instability in the time domain. The time difference between two signal transitions should be a fixed
value, but noise and other effects cause variations.
Noise
Electromagnetic interference between other electronic devices such as mobile phones, motors, etc. and the
DVI cable are coupled onto the signal. Too much noise results in increased jitter.
