Tektronix WVR4000, Руководство по обслуживанию

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Theory of Operation
XGA to DVI Adapter The white adapter supplied with the unit converts the DVI output to a standard
XGA connector, typical of most analog monitors. No adapter is normally required
to connect the DVI output directly to a DVI display.
Main Board
Reference Input The Reference input is a passive loopthrough, which is AC coupled and buffered.
The reference signal is applied to a sync separator whose output is supplied to the
DSP FPGA, where the timing information is derived.
Digital Waveform
Processing Engine
The data stream from the SDI video input is applied to the waveform processing
FPGA. This block deformats, up-samples, interpolates, demodulates, and
otherwise processes the data to generate the signals needed to create the displays.
Rasterizing Engine
The Rasterizer engine resides in the same DSP FPGA as the waveform processing
FPGA. This block builds up the variable intensity images in the fast static RAM.
For each pixel of the display, the Rasterizer Engine increments the intensity of that
pixel every time the waveform hits its coordinates. As a result the waveform areas
hit more frequently are brighter. For any given frame the intensity map is built up
in one memory chip and read out of the other. The functions swap on the next
fi eld.
Recursion and Picture
Processing Engine
The output of the rasterizer feeds the picture and recursive processing engine
in the second large FPGA. This engine adds the previous frame to the present
frame to reduce
fl icker and improve brightness. It also converts the picture and
waveform signals from the input rate to 59.94 Hz frame rate to work with the
XGA monitor. The picture and waveform data combine with the graphics and
audio bar information from the control processor, and then output to the XGA
display drive. Note that the parallel data from the serial digital input connect
directly to this FPGA to provide the picture display functionality, bypassing the
waveform processing engine, which is the DSP FPGA.
Control Processor
The control processor is in charge of all the operational modes in the instrument.
It draws the audio bars, communicates with the front panel through SPI signaling,
and controls most other internal devices though either the SPI or the I
2
C serial
buses.
The control processor interfaces to the Ethernet through a dual rate connection.
This allows the network connection to run at 10 or 100 MB/s. The control
processor has an internal USB 1.1 port that it uses to interface to the USB.
6 WVR4000 and WVR5000 Service Manual