Tektronix HDVG1, Руководство по обслуживанию

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HDVG1 HDTV Digital Video Generator Service Manual
3- 1
Theory of Operation
This discussion provides an overview of the HDVG1 Generator module. For
information about the TG2000 Platform mainframe, refer to the TG2000 Signal
Generation Platform Service Manual .
The HDVG1 Generator module is a 10-bit precision, digital video test signal
generator for HDTV digital signals. Output signal data is stored in fast access
memory (Line Memory) which has been loaded from the NVRAM over the CPU
bus. An overlay data modifier (which is actually an integral part of the fast
access memory) inserts data from the overlay memory into the fast access
memory data stream to create circular patterns, cursors, text characters, and logo.
For HDTV signal generation, Cb and Cr data are multiplexed in the data memory
and then further multiplexed with the Y data to produce the HDTV formatting.
The multiplex switching causes the data mux to output the data sequence in the
following form: Y--Cb--Y--Cr.
The Audio Coprocessor adds embedded audio data.
The coprocessor output containing all the added data is serialized for the module
serial output. There are three serial outputs.