Theory of Operation
3- 2
WVR610A & WVR611A Waveform Rasterizers Service Manual
Serial Digital Input
The serial digital signal inputs are passive loop-throughs, so they must be
terminated to operate properly. The two inputs go through a 2-to-1 multiplexer
and are then are applied to the cable equalizer and the rest of the serial-to-parallel
conversion circuit. The output of this section is parallel data and a 27 MHz
clock.
Composite Input
The Composite input also has passive loop-through capability. If unterminated,
the signal appears twice as large as it should. The two sets of inputs go through a
2-to-1 multiplexer; then the selected signal can be clamped, if selected by the
user. After the clamp, the signal is filtered and then applied to an A-to-D
converter to generate a 12-bit parallel signal. There is also a sync separator to
generate timing information and a picture decoder. The output of the picture
decoder is very similar to the parallel data from the serial digital input. The sync
from the input is passed on the WFM FPGA where the processing is done in the
digital domain including the sub-carrier regeneration and demodulation.
Reference Input
The Reference input is a passive loopthrough similar to that of the Composite
input. The buffered signal is clamped and then digitized to generate a 10-bit
stream. A simple, sync separator is used to generate timing information which is
sent to the waveform processing FPGA. As on the composite input, the sync
from the reference is passed on to the WFM FPGA where the processing is done
in the digital domain.
Digital Waveform Processing Engine
The parallel data streams from all three video inputs are applied to the waveform
processing FPGA. This block up-samples, interpolates, demodulates and
otherwise processes the data to generate the signals needs to create the displays.
Rasterizing Engine
Inside the same FPGA as the waveform processing is the Rasterizer engine. This
block builds up the variable intensity images in the fast static RAM. For each
pixel of the display, the intensity is incremented every time the waveform hits
that coordinate. This results in a display that is bright where the signal is most of
the time and dim where it has only passed only once or a few times. For any
Summary of Contents for WVR610A
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Page 14: ...Table of Contents x WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 18: ...Service Safety Summary xiv WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 22: ...Preface xviii WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 23: ...Specifications...
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Page 53: ...Operating Information...
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Page 90: ...Operating Basics 2 36 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 132: ...Changing Instrument Settings 2 78 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 139: ...Theory of Operation...
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Page 147: ...Performance Verification...
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Page 201: ...Adjustment Procedures...
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Page 204: ...Adjustments 5 2 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 205: ...Maintenance...
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Page 228: ...Repackaging Instructions 6 22 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 229: ...Options...
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Page 235: ...Diagrams...
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Page 243: ...Replaceable Electrical Parts...
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Page 246: ...Electrical Parts List 9 2 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 247: ...Replaceable Mechanical Parts...
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