MIRR explanation : the light reflected in the tracking point is at the track or mirror

DFCT explanation : reflecting mirror defects, defects is high , when no defect is low .

FOK explained : reflects the focus is OK

7, RF signal asymmetry correction circuit ( see figure )

For some reason , RF communication signal will appear asymmetries will greatly affect the generation of channel bits and the channel bit clock signal on the spindle servo is great, the asymmetry correction circuit is equipped with the chip , the purpose of the DC component extermination , smoothly remove the channel bit clock signal. Pin 48 is the output of the asymmetry correction circuit through an external low-pass filter circuit and from the input pin 49 , pin 62 is asymmetric correction switching control circuit terminal , a high level is open, if the control circuit, 57 feet is a constant current source input , ensure that the circuit work .

 

Fourth, the decoding circuit

1, CL8830A Introduction

U.S. core decoder circuit C-CUBE company's fourth generation MPEG-2 decoder chips CL8830A, it is compared with the third generation CL8830 (N108D, N350D was used ) , the main difference in the machine re- repeat function is implemented sing. A 8032 -chip microprocessor , PAL / NTSC video encoder , CD-ROM decoder , MPEG1 and MPEG2 decoders , A / D converter, and a variety of sound effects 24bit audio processing DSP. Solutions CL8830A main audio and video compression work is completed , the use of built-in CPU mode , it also performs the same function of the CPU , the external control circuit means , within it there is an audio DSP , and A / D converter , the processing various sound effects , to achieve beautiful sound functions.

Peripheral CL8830A there SDRAM ( random access memory ), EPROM ( there CL8830A burn internal microcode , machine control program , OSD display data, etc. ) . IC M6631 is an audio D / A converter converts the PCM audio data into an analog output signal CL8830A stereo output . IC74HC04 six inverters , used in conjunction with 27M crystal oscillator to generate clock for decoding use . Another feature of this machine is that it can carry eight games feature , it is by CL8830A multifunction pin to complete, when the disc into the game , the program makes CL8830A first disc as a VCD read, and saves the user selected to be read into the game data SDRAM up, then start the game mode , this time , CL8830A part pin ( 23-27 feet ) function will change , implementing a game .

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