Tektronix WVR4000, Руководство по обслуживанию

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Theory of Operation
LTC LTC inputs come from the remote connector on the REF I/O board where it is
converted from differential to single-ended. The LTC signal is applied to the
waveform processing FPGA, which decodes the time code information.
NOTE.
The FPGAs decode VITC signals digitally.
Front Panel
The front panel contains a small processor which communicates with the control
processor through SPI signaling. Reprogramming can be done through SPI as
well, if the front panel processor
fl ash code needs to be updated.
Audio
The audio capabilities reside on the main board and the backplane board. Audio
supports digital embedded and AES/EBU monitoring.
Audio Processing
The audio processing engine uses the DSY FPGA, whose main function is to
calculate the peak values for the selected meter ballistics (response characteristics).
The audio data has two paths to the display. On one path, peak values are sent to
the control processor which then plots the bar display. On the second path, raw
data samples are sent to the waveform processing engine which interpolates and
plots it to generate the lissajous, or “phase,” display.
Audio Inputs
There are two basic audio input paths: AES and embedded. AES inputs are
accepted at rates up to 192 kHz.
The embedded audio path starts at the waveform processing engine. First the
audio samples are extracted from the serial digital video data and then multiplexed
into the AES decoder. They then follow the same path as the AES data.
WVR4000 and WVR5000 Service Manual 7