Block Diagram, Power Supply, Communications

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:

ICs Checked During Start Up

	Name	Number	Purpose

1.	Flash ROM	IC205	Start up program instructions

2.	Hybrid Gate	IC601	Expansion port for System Control
	Array		IC202 to indirectly communicate with
			others on the parallel bus.

3.	SRAM	IC204	IC202’s local memory

4.	AV Decoder	IC401	Audio (AC-3) and Video (MPEG 2)
			decoder

5.	ARP2	IC303	CD/DVD data processing and
			separation

6.	Servo	IC701	Analog servo control

7.	Audio DSP	IC501	Dolby Prologic, Rear channel delays,
			5.1 channel downmixing to 2 channels

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.