Tektronix WFM8200, Руководство по обслуживанию

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Theory of Operation
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, and controls most
other internal devices though either the SPI or the I
2
C bus. Audio data is input to
the control processor via the 8 bit HPI bus.
The control processor interfaces to the Ethernet through a dual rate connection.
This allows the network connection to run at 10 or 100 MBps.
LTC LTC inputs come from the remote connector. The LTC signal is applied to an A/D
converter and then input 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 the SPI if
the front panel processor
fl ash code must be updated.
Composite Input Option CPS
The Composite inputs are also passive loop-throughs. If unterminated, the signal
appears twice as large as it should. The inputs are either AC or DC coupled,
depending on the DC Restore setting. The selected input signal is
fi ltered and
applied to an A-to-D converter to generate a 14-bit parallel signal, which is routed
to the DSP FPGA on the Main board, where it is demodulated in the digital
domain.
Audio Options AD and DPE
The audio option (if installed) resides in the module slot closest to the power
supply. There are two audio options available.
Option AD adds Analog Audio Monitoring (2 sets of 6 channel Analog Audio
inputs and 8 channels of Analog Audio outputs) and 16 channels Embedded
and AES/EBU Digital Audio support (8 channels at a time). This option
is available for all models.
Option DPE adds Option AD capabilities plus support for decoding and
monitoring Dolby E and Dolby D Audio. This option is available for all
models.
2–4 WFM8200 and WFM8300 Waveform Monitors Service Manual