Sony D8MM-01, Training Manual

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15
Video Signal Block
Overview
The purpose of this section is to discuss the three different video paths.
The three paths are D8 record, D8 playback and analog 8mm playback.
We will discuss this in a block level only since component troubleshooting
is not necessary. This will help to give you an overall idea of the three
signal paths.
D8 Record
Recording can be done either by using the signal from the camera sec-
tion, analog line input or through the IEEE1394 input.
Camera Front End Processing
The camera front end-processing block contains the lens, CCD, timing
generator and associated circuitry. This section processes the CCD im-
age data and outputs 10 bit CCD Data to the Tanuki (Traffic Cop) section.
Tanuki (Traffic Cop)
A portion of this section’s function is to process the information from the
camera front end processing block. This would function similar to a por-
tion of the core IC in an analog 8mm camera. This IC outputs data to the
DSP/Compression block.
Line In
When a line input signal is to be recorded, it is input to a A/D Converter on
the main board. The signal is digitized and output to the compression
section. This data is sent on the same bus as the data from the camera
section.
DSP/Compression
This section compresses the data, reducing the amount of video data
from 162 Mbps to 25 Mbps. It also codes the data and interleaves it with
the ITI, Audio and Subcode data. This data is then streamed to the Head
Amplifier. It also outputs the compressed video to the IEEE1394 inter-
face, as well as analog signals for the viewfinder and Line Out.
Head Amp
The head amp adds a clock signal and amplifies the data. It is then ap-
plied to the heads and recorded on the tape.
D8 Playback
Head Amp
The head amp receives the signal from the heads and amplifies and equal-
izes the signals from each head. This section also inputs the RF signal to
a PLL circuit, which produces a stable clock for processing the head data.
DSP/Decompression
This block separates the data back in to its various sectors. The video
data is decompressed and restored back to an analog video signal. It
outputs analog signals to the viewfinder and Line Out, as well as a digital
signal to the IEEE1394 interface.
Analog 8mm Playback
Head Amp
The head amp creates a separate RF signal if an analog tape is played
back.
8mm Playback RF Amp
This block separates the Y RF and C RF signals.
Camera Front End
The C RF signal is applied to this block. This block digitizes the C RF
signal and applies it to the Traffic Cop block via the 10 bit bus.
Tanuki
This block receives the Y and C RF signals and demodulates them. It
outputs analog Y and C to the A/D converter. The A/D converter is the
same one used by the Line In circuit in D8 record. Its output is applied to
the DSP/Compression block.
DSP/Compression
The signal is sent to this block so that it can be output to the line out
and viewfinder. It is also compressed so that it can be output to the
IEEE1394 interface.