FIELD OF INVENTION
The present invention relates to high reliable, EMC/EMI prone video switching
technique/circuitry to enable analog video switching of high speed video signals. The circuitry
utilizes a minimum space of 60mm X 60mm on a multilayer printed circuit board (PCB). A
general purpose microcontroller is interfaced with video switch through a shift register and a
CPLD. Circuit can be used for individual as well as multiple video input-output.
BACKGROUND OF THE INVENTION
The electronic components used in the invention had been gone through severe working
environment and had been tested satisfactorily for its working in airborne applications.
Mechanism comprises of the good noise reduction technique and excellent impedance
matching to handle the low amplitude video signals for longer distance. The invention is usable
under single as well as dual power supply applications.
SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide cross-point video switching
architecture interfaced with general purpose microcontroller (at least 16 bit) and CPLD.
In accordance with second aspect of present invention is to provide a low power switching
architecture.
In accordance with another aspect present invention is to provide highly reliable integrated
switching architecture using minimum space on PCB.
In accordance with yet another aspect present invention is to provide a high frequency video
switching architecture having high bandwidth and low difference phase/difference gain error.
Advantage of the present invention is that it is common for RGB and Y/C video standards and
video switch used provide the excellent impedance matching with the external video circuitry.
BRIEF DESRIPTION OF DRAWING
Figure 1 call on block diagram of video switching architecture. In this video switch interfacing
with microcontroller along with CPLD and parallel to serial shift register has been shown.
DETAILED DESCRIPTION
As per figure 1 present invention comprises video cross-point switch that utilizes its non
blocking feature to route incoming video signals from different sources to different video-on
demand systems. Shift register takes parallel data input from microcontroller and provides
serial data output to SPI interface on video switch. Along with this video switch also accepts the
control and reset lines directly from microcontroller and CPLD.
Switch functions in two modes. In first mode switch works as individual output address mode
while in second it works as complete address mode. Mechanism has also been provided to alter
the gain of the output video signals in case amplitude is very low to reach the destination. The
architecture accepts single ended video signals at its input lines and transmits single ended
output signals which can be made differential for its direct use on video-on demand signals. Its
good impedance matching to its input and output make it very useful with respect to noise
reduction and ignoring distortion.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We claim

1. Architecture of a cross-point non blocking video switch to route input video signal (maximum 16) from selected any input video source to any output video-on demand systems (maximum 16).
2. Serial peripheral interface (SPI) feature of the switch using a general purpose microcontroller and a shift register. Digital data is fed to the switch through this SPI interface to route the signal as per user requirement.
3. Single input and single output mechanism with programmed buffer gain and good impedance matching.
4. High frequency and very smooth video switching architecture utilizing minimum space and low power consumption property.
5. Property of the architecture for switching both RGB and Y/C videos with satisfactory thermal and signal integrity of the circuitry. ,TagSPECI:As per Annexure-II