Tektronix WFM6100 Opt. MB, Руководство по обслуживанию

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Theory of Operation
2- 4
WFM6100, WFM7000, and WFM7100 With Option FP Service Manual
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 bus. A few parts communicate through other bus types like JTAG or SPI.
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 MB/s.
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 SPI as
well, if the front panel processor flash code needs to 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 may be either AC or DC coupled
(user selected). The two sets of inputs go through a 2-to-1 multiplexer, then the
signal is filtered 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
processed (regenerates sub-carrier and demodulates) in the digital domain.
Control Processor
LTC