Hitachi DV-P505E, Service Manual

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6 Chapter 1
Functions of each IC
The following is the description of the functions of each IC:
1. A/V PROCESSOR (IC1201)
It is a single-chip A/V processor that integrates several modules functioning MPEG video decoding, DVD
system navigation, Content Scrambling System(CSS), DolbyTM Digital (AC-3), DTS and MPEG audio
decoding respectively.
Data input is separated into video data and audio data. Then the two data is decoded and output as
digital video and digital audio respectively. A build-in RISC transfers data and executes presetting and
control of each modeule.
System clock, clock of video interface signals operate by inputting 27MHz respectively.
2. Flash Memory (IC1601)
A 4Mbits flash memory is used. It stores program of the preceding build-in RISC and its access is
controlled by said RISC.
3. BUFFER SDRAM (IC1202~1203)
Two 16Mbits SDRAM are used. A/V processor controls it and it is used to decompress audio and video
compressed by MPEG.
4. EEPROM (IC1604)
Video circuit (DEC substrate)
8bit YC
R
C
B
digital video stream (Parallel) output from A/V processor are input to video encoder
ADV7170(IC2201). Video encoder is preset in master mode that generates reference signals and
receives 27MHz from system clock X1 and outputs Horizontal, Vertical synchronous signals to A/V
processor.
By presetting of internal register, video encoder generates:
1. NTSC (North America, Japan, Taiwan)
2. PAL (Europe, Asia)
standard analog video signals.
No. IC Functions
Operating
Voltage
1 IC1201 A/V PROCESSOR Execute data transfer, presetting and control of each IC.
Execute decompression (decoding) of data compressed by
MPEG, AC3, DTS.
3.6V
2 IC1601 FLASH MEMORY Store memory for A/V processor’s RISC software 5V
3 IC1202~IC1203 Memory used for decompression (decoding) of data
compressed by MPEG and control by A/V processor. 3.3V
4 IC1604 EEPROM Store program code of system 5V