[XCM-017] A/D, D/A Demonstration. Display a video signal on DSO Nano V2 using Xilinx Hi-speed Transceiver.

 

The Pattern generator (GV-241) outputs high frequency signals for DSO Nano. In order to monitor signals with DSO Nano, the FPGA slows the rate of data down in 1/100 of original and outputs to UTL-012, isolated 16-bit D/A conversion board, to convert digital data to analog data.

 

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Bottom waveform is raw signal generated by pattern generator. (2us/Div)
Top is slow-downed waveform by FPGA. A down pulse is added manually for capture.

DC component of a signal is not replayed in DACed waveform because of a limitation comes from A/D converter’s input circuit (About 100kHz or below will be cut off). High-frequency component of signal is reduced its amplitude because of a limitation comes from D/A converter’s slew rate.

Captured A/D data in Virtex-5. (using ChipScope)

Test video signals make a monochrome striped pattern on a monitor. Sparse and dense pattern matches with above waveform.

 

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DSO Nano displays authentic-looking waveform on it.

 

Original high-speed signal cannot be captured without the system.

As you can see, video signal was captured by an affordable oscilloscope.
This demonstration is just only for a demonstration and has no practicality. But we are grad if this gives you some hints for using our products.

 

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- Data Rate : 2Gbps
- Reference Clock : GREFCLK 100MHz （Multiple on-boarded 50MHz into 100MHz by PLL)

 

- RX Comma Alignment : Enable(K28.5)

 

- Clock Correction : Enable (K28.5), Sequence Length:１

 

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LTC2274 is a 105Msps, 16bit A/D converter. The captured analog data is converted into 8B10B encode serial data, so it is easy to connect to FPGA high speed serial interface (RocketIO, GTP,,)

DSO Nano V2 is Seed Studio's affordable pocket-size oscilloscope. I choose this because of just only price. It is very accessible. The DSO Nano V2's spesification is below:

 

( Captured user manual, at the date of 2011/02/15)

 

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