Philips-DVDR-985-Service-Manual-2电路原理图.pdf

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1、Philips DVDR985Technical Training ManualPhilips Service and Quality/TrainingOne Philips DriveKnoxville, TN 37914-1810P. O. Box 14810PH: 865-521-4397FAX: 865-521-4818EMAIL: TECHNICAL.TRAININGPHILIPS.COMIntroductionThis Manual is intended for use by the ServiceTechnician. The first portion of this man

2、ual con-tains a basic description of disc based data play-back and recording technologies. SelfDiagnostics are included to aid in troubleshoot-ing. Technical Descriptions of the circuitry is fol-lowed by a Troubleshooting Section. The DVDR985 is the forth in a line of DVDrecorders. The DVDR1500 was

3、the first.Recordings can be made from broadcast trans-missions, and from other analog or digitalsources. The DVDRW format allows the user torecord and erase a disc many times. The record-ed discs will play on most existing and futureDVD players. The DVDR985 has a connectionfor DV or Digital camcorde

4、rs via an I-Link orFirewire connection. This connection technicallyis called an IEEE 1394 connection. This machinerecords on 4.7Gbyte DVD+R and DVD+RWdiscs. This machine uses a real-time MPEG2Variable Bit Rate, VBR, Video encoder. TheDVDR985 plays back DVD Video, Video CD,Audio CD, CD-R, and CD-RW d

5、iscs.Its many features include: Favorite SceneSelection for easy editing, Index Picture Screenfor instant overview of contents, Digital TimeBase Correcter, Digital Audio output (DTS, AC-3, MPEG, PCM), TruSurround for 3D sound,Zoom + Perfect Still. It is Widescreen, 16:9compatible, and has a Universa

6、l RemoteControl, 20 disc resume, Disc Lock, and OneTouch Recording. Virgin ModeThe DVDR985, when first hooked up, needs toget information from the user about what lan-guage and what local broadcast system theunit is going to operate with. Use the remote tomake those selections. The unit will not ope

7、rateuntil this process is completed. If you want therecorder to start up in Virgin mode, unplug therecorder. Plug the recorder in again while hold-ing the STANDBY-ON button.DVD BasicsPhilips with nine other manufacturers chose aformat specification for DVDR and RW on March16, 2001. This new format u

8、ses Real Timerecording. Its recording is compatible with DVD-Video, and DVD ROM. The data blocks use loss-less linking. The physical layout matches veryclosely that of DVD ROM. See Figure 1. It alsouses Direct Overwrite when a RW disc is used.Laser TechnologyCDs use a red laser created by a diode an

9、d lenssystem often called a Light Pen. Refer to Figure2. The narrow beam of light is focused onto thereflective layer of a disc. At the instant that focusis achieved, the disc is spun. The laser starts onthe innermost tracks of the CD and reads out-ward. At the beginning of the disc is the Table ofC

10、ontents. At the bottom of the Light Pen areMonitoring Diodes. The Monitoring Diodes pro-vide information about focus and tracking. Datais retrieved from the disc in the form of pulses ofFigure 1 DVD ROM Disc1light reflecting from the disc. The pulses arecreated by Pits in the Reflective Layer of the

11、disc. The Pits reflect less light than the intactsurface of the Reflective Layer, called Lands. Disc Mechanical LayoutThe DVD and CD share much of their tech-nology. We will start with CDs and work ourway to the DVD. The CD is a plastic disc120mm in diameter, with a thickness of1.2mm. Refer to Figur

12、e 3. It has a silver col-ored Reflective Layer. The maximum playingtime for a music recording on a CompactDisc, CD, is 74 Min. The CD is less vulnerable to damage than ananalog record. That does not mean it doesnot have to be treated with care. Dirt andheavy scratches can interfere with playability.

13、Figure 2 CD Laser OperationFigure 3 Mechanical Layout of a CD.2As shown in Figure 4, the CD is subdivided intothree parts: the Lead In Track, the ProgramArea, and the Lead Out Area. These three sec-tions together are considered the InformationArea. There is a hole in the center for holdingthe disc.

14、The disc is held between two equallysized concentric rings. The rings have an innerdiameter of 29mm and an outer diameter of31mm. The Data on the disc is recorded on a spiralshaped track with pits and lands. The reflectiveside of the disc contains the tracks.The production of a disc is a high tech p

15、rocessexplained in Figure 5. The process starts withglass that is photo etched. The glass is silverplated and is used as a form for a metal cast.The metal cast is used to stamp a nickel MotherStencil. The Mother Stencil is used to stamp theSon Stencil. Son Stencils are used to stamp thefoil of the d

16、iscs. A protective layer and label areadded.Read ProcessThe Servo circuit is responsible for focusing thelaser and moving the Light Pen to follow the spi-raling tracks on the rotating disc. The digital HighFigure 4 - The DiscFigure 5 - Creating a CD3Frequency information, HF, is demodulated andstore

17、d in RAM. When the RAM is half full, thedata is fed out to the Digital to AnalogConverters. The speed of the rotating disc isservo controlled to keep the RAM half full. Theanalog signals are amplified and sent to the out-put connectors.Record Once TechnologyDisc Mechanical Layout From an external po

18、int of view, a DVD is thesame as the CD. Recordable media creates theneed for three physical layouts. There are threepossible states of a disc: a blank disc, a partiallyrecorded disc, and a full or finalized disc. Thedifference is in the way the Information Area isdivided. The Information Area of a

19、blank discextends from 22.35 mm centered on the disc to59 mm centered on the disc. Refer to Figure 6. A partially recorded discs Information Area hasfour sections: a PCA/RMA area, a Lead In Area,a Recorded Program Area, and a RecordableProgram Area. See Figure 6 for the dimensions.The PCA Area is th

20、e Power Calibration Area,PCA. The RMA Area is the RecordingManagement Area. A fully recorded or finalized discs InformationArea has three sections: A lead in Area, theProgram Area, and the Lead Out Area. SeeFigure 7 for the dimensions. The discs recordable layer contains major differ-ences from that

21、 of a stamped disc. The blankdisc has a Pre-groove stamped into the record-able layer of the disc. This is polycarbonant forDVD+Rs and organic dye material forDVD+RWs. This spiral Pre-groove is for theServo circuit to provide a mechanical reference Figure 6 A Partially Recorded Disc.Figure 7 Fully R

22、ecorded or Finalized Disc4during recording. The dye based RW recordablelayer provides a reflectivity of 40% light returnand 70% light return. 40 percent reflectivity rep-resents Pits and the 70% represent the Lands. Record ProcessThe record process shares most of its mechani-cal operation with that

23、of the play process. Themain difference is how the Servo is locked to thedisc. The Servo follows the Pre-groove for RadialTracking and disc speed. The speed of the discis locked to a wobble signal that is part of thespiral grove stamped into the disc. The intensity of the laser beam is modulatedfrom

24、 playback intensity to write intensity. As thedisc reads the Pre-groove, the laser arrives at aposition where a Pit is to be formed. The laserpower increases from 4mW to 11mW. This raisesthe temperature of the disc to 250 degreesCelsius. The recordable layer melts, reducing itsvolume. The polycarbon

25、ate flows into the spacevacated by the dye. The modulation from readlaser power to write laser power forms a pit andland pattern effectively the same as a prerecord-ed disc. Re-recordable TechnologyDisc Mechanical LayoutDisc usage mechanically is identical to therecordable media. The only difference

26、 is thechemical make up of the recordable layer. Therecordable layer is made up of an alloy of silver,indium, antimony and tellurium. Re-Recording Process The Re-Record process shares much of its oper-ation with that of a CDR. The blank discsInformation Area is in a polycrystalline state.During reco

27、rding, the laser power is modulatedfrom 8mW to 14mW. 8mW is the playback laserpower and 14mW is the record laser power. Thepolycrystalline state of the recordable surfacechanges, or melts at 500-700 degrees C into anamorphous state. The melted, amorphous areasreflect light less than the crystalline

28、areas, creat-ing a pattern similar to the stamped CD. A majordifference of CDRWs from CDRs is the ability toerase. The Erase ProcessTo Erase a CDRW disc, the recordable layermust be returned to its polycrystalline state. Thisis done by heating up the temperature of therecorded surface to 200 degrees

29、 C. This is lessthan the melting point. This is done at X2 record-ing speed. The slower speed allows time for thealloy to return to its proper state. This takesapproximately 37 min. Some software erases thejust the TOC on the disc and allows the disc tobe rewritten. This method is not as reliableOve

30、r Writing ProcessOverwriting combines the processes of erasingand writing. When the disc and Light Pen are inposition to start writing the new data, the laserpower starts modulating in the same manner asit does for normal recording with one difference.During the time there is to be a land, the laser

31、power goes to the erase level rather than theplayback level. Figure 8 Mechanical Layout of a DVD5DVDsAll of the previously discussed technologiesapply to the DVD. Like CDs, DVDs are alsostamped into play only discs. In this discussion,we will point out the differences between DVDsand CDs. If you are

32、 new to disc based technolo-gy, you will want to start with the information pre-ceding this discussion.DVD Disc Mechanical DifferencesMost DVDs are single sided, however, the DVDspecification allows for two readable layers, andthe disc can be double sided. We will start ourdiscussion with single sid

33、ed, single layereddiscs. A Digital Versatile Disc, DVD, looks verysimilar to a CD. Refer to Figure 8. The ClampingArea is larger, starting at 11 mm centered to 16.5mm centered. The Lead In Area is smaller,measuring 22.7 mm centered to 24 mm cen-tered. The Information Area is limited to 116mmcentered

34、.Two of the big differences between DVDs andCDs are the Pit and Land sizes, and the trackwidths. Refer to Figure 9.The Manufacturing process of a DVD is compa-rable to that of a CD. The main difference is thethickness. The DVD can be a double sided prod-uct. Each side is .6mm. The two sides are glue

35、dback to back, producing 1.2mm total thickness. Figure 8 - DVD Mechanical LayoutFigure 9 DVD and CD Pit Structure.CDDVD6WobbleA Pre-groove is stamped on writable discs. All recordable DVD media types feature a micro-scopic wobble groove embedded in the plasticsubstrate. This wobble provides the reco

36、rderwith the timing information needed to place thedata accurately on the disc. During recording,the drives laser follows this groove, to ensureconsistent spacing of data in a spiral track. Thewalls of the groove are modulated in a consistentsinusoidal pattern, so that a drive can read andcompare it

37、 to an oscillator for precise rotation ofthe disc. This modulated pattern is called a wob-ble groove, because the walls of the grooveappear to wobble from side to side. This signal isonly used during recording, and therefore has noeffect on the playback process. Among the DVDfamily of formats, only

38、recordable media usewobble grooves.Dual Layer DiscsTwo information layers are separated by a thintransparent layer. Refer to Figure 11. The firstlayer is partially transparent. This allows the sec-ond layer to be read through the first layer. Bothlayers are read by controlling the focus. Thereare tw

39、o methods for reading the data of a DualLayer disc, PTP and OTP. Refer to Figure 12.PTP is Parallel Track Path. That means the LeadIn and Out Areas of the two layers correspond toeach other. Each Lead In Area is on the innerportion of the disc, and the Lead Out Area is onthe outer portion of the dis

40、c. This is useful to linkdata between the layers.Figure 11 Dual Layer DVD7Figure 10 - Wobble PregrooveThis allows instant access to the additional dataor scene. OTP is Opposite Track Path. Thismethod links the end of one layer to the begin-ning of the other. The Lead In Area is still on theinner por

41、tion of the disc. There is a Middle TrackArea on both of the layers located on the outerportion of the layers. The Middle Track Area linksthe data on the two layers together. The LeadOut Area is on the second layer on the inner por-tion of the disc.CapacityBecause a stamped DVD can be Dual Layeredan

42、d Double Sided, there are four different capac-ities. Refer to Figure 13. These capacities strict-ly pertain to raw data. The time available forVideo and Audio has many extra factors thatdetermine the length of time on each side orlayer. The picture complexity and the amount ofmovement in the pictur

43、e affect compression andtime on a disc. The number of languages affectthe time on a disc. The type and quality of theAudio has an affect on the time also. It can bemono, stereo, or AC-3. Therefore, the mediaitself determines the capacity in time on the disc.Figure 13 DVD Multi-Layered Capacities8Fig

44、ure 12 PTP and OTP LayoutDescriptionThe End User/Dealer Self Diagnostics work with-out the need for other equipment. A number ofhardware tests are automatically executed tocheck for faults in the recorder. The diagnosisends with a “FAIL” or “PASS” message. If themessage “FAIL” appears on the display

45、, an ErrorCode is displayed. If the message “PASS”appears, the tests have been executed success-fully. There can still be a failure in the recorder.The tests do not cover the complete unit. Thefollowing list describes the tests being preformedwhile the test number is being displayed on theFront Pane

46、l. To place the unit in the Self TestMode, hold the Play pushbutton on the FrontPanel while suppling AC power to the unit. Thedisplay counts down numerically the test it isperforming. The following is a list of the test displayed as:“Test Number” is displayed on the Front Panel“Name”of the testDescr

47、iption of the test22SdramWrRChecks all memory locations of the 4MbyteSDRAM21HostdDramWrRChecks all the DRAM connected to the micro-computer on the Digital Board20HostdI2cNvramChecks the data line (SDA) and the clock line(SCL) of the I2C bus between the host decoderand NVRAM19SAA7118I2cChecks the int

48、erface between the Host I2C con-troller and the SAA7118 Video Input Processor18VideoEncI2cChecks the interface between the host I2C con-troller and Empress17AudioEncI2cChecks the I2C connection between the hostdecoder and Empress16AudioEncAccessTests the HIO8 interface lines between the hostdecoder

49、and the audio encoder15AudioEncSramAccessChecks the access of the SRAM by the audioencoder (address and data lines).14AudioEncSramWrRTests the SRAM connected to the audio encoder13AudioEncInterruptTests the interrupt line between the host decoderand the audio encoder12VsmAccessChecks whether the VSM interrupt controllersand DRAM are accessible11VsmInterruptChecks both interrupt lines between the VSMand the host decoder10VsmSdramWrRTests the entire SDRAM of the VSM9Automatic Self Diagnostic Modes(End User/Dealer Script Interface)