Block Diagram
There are four major stages within this DVD player. They operate in this sequence to produce the discs’ video and audio:
·Power Supply
·Communications
·Servo Control
·Video and Audio Processing
Power Supply
The power supply block delivers five different voltages. Ever 5V is the only voltage present when the unit is plugged into AC. Ever 5V powers Interface IC201 to switch on the remainder of the voltages when it re- ceives the power ON (P Cont) command.
Communications
Plug In
At plug in, Interface IC201 powers on the unit for 1.3 seconds, keeping the display dark. During this time there is a brief communication between Interface IC201 and System Control IC202 on the serial bus. At the con- clusion of this communication “handshaking”, the front panel Dolby Digital indicator lights and quickly extinguishes as the unit powers off. The front panel red standby light is on during the entire initial communication, never turning green when momentarily powering up at plug in.
Power ON
At power ON, the red standby light turns to green and the power supply is turned on. After another brief communication between IC201 and IC202, IC202 retrieves and implements the start up program stored in Flash Memory IC205.
The start up program requires IC202 to check for the presence of these six ICs on the parallel bus and IC501 on the serial bus:
7
ICs Checked During Start Up
| Name | Number | Purpose |
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1. | Flash ROM | IC205 | Start up program instructions |
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2. | Hybrid Gate | IC601 | Expansion port for System Control |
| Array |
| IC202 to indirectly communicate with |
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| others on the parallel bus. |
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3. | SRAM | IC204 | IC202’s local memory |
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4. | AV Decoder | IC401 | Audio |
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| decoder |
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5. | ARP2 | IC303 | CD/DVD data processing and |
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| separation |
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6. | Servo | IC701 | Analog servo control |
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7. | Audio DSP | IC501 | Dolby Prologic, Rear channel delays, |
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| 5.1 channel downmixing to 2 channels |
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If an IC does not reply, IC202 instructs IC201 to power off the set.
Servo Control
At the successful conclusion of the start up program, IC202 retrieves servo parameter data from EEProm IC201 using the serial bus. Then IC202 communicates with expansion port HGA IC601. IC601 relays the infor- mation to other ICs connected to it. One of those ICs is IC701. Servo IC701 is instructed to reset the base unit mechanism to the initial position and confirm it:
·Tray closed
·Tilt servo at mid position
·Sled returned to home position
If the initial position is not confirmed before a time limit (“time out”), IC201 will power off the set. Confirmation comes from IC701 through IC601 to IC202.
IC202 then sends commands back to servo IC701 for disc detection.
