Unified audio/video interface for a digital video disk system

• US 6,311,014 B1
• Filed: 12/24/1997
• Issued: 10/30/2001
• Est. Priority Date: 12/24/1997
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Nguyen, Loc, Zhu, Li
• Primary Examiner(s): TRAN, THAI Q
• Application Number:
  US08/997,886
• Time in Patent Office: 1,406 Days
• Field of Search: H04/N.576, H04/N.592, H04/N.5781, H04/N.710, 386/1, 386/45, 386/33, 386/46, 386/125, 386/126, 386/111-112, 348/7-16, 348/552, 348/553, 348/571, 348/725, 369/1, 369/13-16, 369/47-48, 369/53-54, 360/39, 360/55, 360/48, 345/326, 345/327-329, 345/333-334, 345/961, 345/970, 345/971, 455/3.1, 455/3.2, 455/4.1, 455/4.2, 455/6--
• US Class Current: 386/206
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

An interface for a digital video disk system utilizing a small number of pins which allows a requesting device to initiate data requests and which avoids the phenomenon of lock-up. The interface includes an input interface terminal at which a data request signal from an output device is received in a first mode and at which a sampling signal is received from the output device in a second mode; a first output interface terminal at which a sampling/synchronizing signal is transmitted from the source device to the output device in the first mode, the sampling/synchronizing signal synchronizing and sampling the data request signal, and at which a first synchronizing signal is transmitted from the source device to the output device in the second mode, the first synchronizing signal synchronizing data output; at least one data output interface terminal at which requested data is transmitted from the source device to the output device in the first and second modes, a second output interface terminal at which a second synchronization signal is transmitted from the source device to the output device at the start of data transmission in the first mode; a third output interface terminal at which a data strobe signal is transmitted from the source device to the output device in the first mode, the data strobe signal latching the requested data, and at which a third synchronization signal is transmitted from the source device to the output device in the second mode, the third synchronization signal synchronizing the left/right audio frames; and a fourth output terminal at which a data error signal is transmitted from the source device to the output device in the first and second modes, the data error signal indicating that the requested data contains an error.

Claims

1. A source device interface comprising:

an input interface terminal at which a data request signal from an output device is received in a first mode, and at which a sampling signal from said output device is received in a second mode;

a first output interface terminal at which a sampling/synchronizing signal may be transmitted from said source device to said output device in said first mode, said sampling/synchronizing signal synchronizing and sampling said data request signal, and at which a first synchronizing signal is transmitted from said source device to said output device in said second mode, said first synchronizing signal synchronizing data output;

at least one data output interface terminal at which requested data is transmitted from said source device to said output device in said first and second modes;

a second output interface terminal at which a second synchronization signal is transmitted from said source device to said output device at the start of data transmission in said first mode;

a third output interface terminal at which a data strobe signal is transmitted from said source device to said output device in said first mode, said data strobe signal latching said requested data into said output device, and at which a third synchronization signal is transmitted from said source device to said output device in said second mode, said third synchronization signal synchronizing the left/right audio frames; and

a fourth output interface terminal at which a data error signal is transmitted from said source device to said output device in said first and second modes, said data error signal indicating that said requested data contains an error.

2. A source device interface according to claim 1, wherein said first mode is a parallel interface mode and said second mode is a serial interface mode.

3. A source device interface according to claim 1, wherein said source device is a digital video disk controller and said output device is a DVD Source Decoder having an MPEG-2/AC-3 decoder.

4. A source device interface according to claim 1, wherein said source device is a digital video disk controller and said output device is DVD-ROM.

5. A source device interface according to claim 1, wherein said data request signal is asserted by changing level from a first level to a second level.

6. A source device interface according to claim 5, wherein said sampling/synchronizing signal samples said data request signal during transmission of each byte of said requested data.

7. A source device interface according to claim 6, wherein said requested data is transmitted so long as said data request signal is at said second level and data remains to be transmitted.

8. A source device interface according to claim 1, wherein said sampling signal samples requested data at a rate higher than a data rate.

9. A source device interface according to claim 1, wherein said data strobe signal latches said requested data on its leading edge and has a pulse width which is programmable.

10. A source device interface according to claim 1, wherein said interface is compatible with the ATAPI standard.

11. A source device interface according to claim 1, wherein a microcontroller is programmed to implement said interface in a data controller of a digital video disk system.

12. A source device interface according to claim 11, wherein said microcontroller directs said interface to operate in said first mode or said second mode.

13. A method of transferring data from a source device to an output device comprising the steps of:

(a) receiving a data request signal transmitted by said output device in a first mode, or receiving a sampling signal from said output device in a second mode;

(b) asserting a sampling/synchronizing signal which synchronizes and samples said data request signal in said first mode, or asserting a first synchronizing signal which synchronizes data output in said second mode;

(c) transmitting requested data from said source device to said output device in said first and second modes;

(d) asserting a second synchronizing signal indicating the start of data transmission in said first mode;

(e) asserting a data strobe signal which latches said requested data into said output device in said first mode, or asserting a third synchronization signal which synchronizes the left/right audio frames in said second mode; and

(f) asserting an error signal when said requested data contains an error in said first and second modes.

14. The method according to claim 13, wherein said data request signal is asserted by changing level from a first level to a second level.

15. The method according to claim 14, wherein said sampling/synchronizing signal samples said data request signal during transmission of each byte of said requested data.

16. The method according to claim 15, wherein said requested data is transmitted so long as said data request signal is at said second level and data remains to be transmitted.

17. The method according to claim 13, wherein said sampling signal samples requested data at a rate higher than a data rate.

18. The method according to claim 13, wherein said data strobe signal latches said requested data on its leading edge and has a pulse width which is programmable.

19. The method according to claim 13, further comprising the step of determining whether to operate in said first mode or said second mode.

20. A digital video disk system comprising:

a channel interface which receives and amplifies data from a disk, and outputs a control signal indicative of scanning conditions of said disk by a light source;

a servo DSP which receives said control signal and controls the scannings of said disk by said light source;

a data path controller which stores said data from said channel interface and outputs said data to one or more playback devices via an interface; and

a microcontroller programmed to implement said interface in said data path controller, said interface comprising;

an input interface terminal at which a data request signal from said one or more playback devices is received in a first mode, and at which a sampling signal from said one or more playback devices is received in a second mode;

a first output interface terminal at which a sampling/synchronizing signal is transmitted to said one or more playback devices in said first mode, said sampling/synchronizing signal synchronizing and sampling said data request signal, and at which a first synchronizing signal is transmitted from said source device to said one more more playback devices, said first synchronizing signal synchronizing data output;

at least one data output interface terminal at which requested data is transmitted to said one or more playback devices in said first and second modes;

a second output interface terminal at which a second synchronization signal is transmitted to said one or more playback devices at the start of data transmission in said first mode;

a third output interface terminal at which a data strobe signal is transmitted to said one or more playback devices, said data strobe signal latching said requested data into said one or more playback devices, and at which a third synchronization signal is transmitted from said source device to said one or more playback devices in said second mode, said third synchronization signal synchronizing the left/right audio frames; and

a fourth output interface terminal at which a data error signal is transmitted to said one or more playback devices in said first and second modes, said data error signal indicating that said requested data contains an error.

21. A digital video disk system according to claim 20, wherein said one or more playback devices include a DVD Source Decoder having an MPEG-1/AC-3 decoder, and a DVD-ROM.

22. A digital video disk system according to claim 20, wherein said requested data is only transferred over one of said plurality of data output interface terminals.

23. A digital video disk system according to claim 20, wherein said data request signal is asserted by changing level from a first level to a second level.

24. A digital video disk system according to claim 23, wherein said sampling/Synchronizing signal samples said data request signal during transmission of each byte of said requested data.

25. A digital video disk system according to claim 24, wherein said requested data is transmitted so long as said data request signal is at said second level and data remains to be transmitted.

26. A digital video disk system according to claim 20, wherein said sampling signal samples requested data at a rate higher than a data rate.

27. A digital video disk system according to claim 20, wherein said data strobe signal latches said requested data on its leading edge and has a pulse width which is programmable.

28. A digital video disk system according to claim 20, wherein said interface is compatible with the ATAPI standard.

29. A digital video disk system according to claim 20, wherein said microcontroller directs said interface to operate in said first mode or said second mode.