System decoder and method using a single memory for a...

Details System decoder and method using a single memory for a... System decoder and method using a single memory for a...

1997-06-02

2001-07-31

Garber, Wendy R. (Department: 2615)

Motion video signal processing for recording or reproducing

Local trick play processing

With randomly accessible medium

C386S349000, C348S716000

Reexamination Certificate

active

06269220

ABSTRACT:

The present invention is based on Korean Patent Application No. 19230/1996, which is incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system decoder and method for an optical disc playback device, and more particularly to a system decoder and method for a digital video (or versatile) disc playback device.
2. Description of the Related Art
The digital video disc, which is one type of digital animation disc medium, is a popularized next generation multimedia storage device for storing high grade images with a high degree of tone quality.
Referring to
FIG. 1
, when playing back a disc
100
, a disc motor
160
starts to rotate at a speed, and the optical pickup, having a head
120
, converts the disc information into a high frequency analog signal (HF) to be transmitted. This HF signal is shaped into a pulse waveform, whereby an eight-to-sixteen modulation (ESM) or eight-to-fourteen modulation (EFM) data stream is delivered to a phase locked loop (hereinafter referred to as “PLL”)
300
and to a system decoder
200
. The system decoder
200
performs demodulation, error correction and descrambling of the (ESM, EFM) data stream. A microcomputer
500
is a device control unit for controlling the overall operation of the entire optical disc playback system. When receiving a data transfer start signal from an audio/video decoder
600
or ROM decoder, which is described below, the microcomputer
500
generates a transfer control signal.
The above mentioned PLL
300
consists of a phase comparator, a voltage-controlled oscillator and a frequency divider, and it generates a first clock synchronized with a signal reproduced from the specific optical disc. A disc drive controller
400
controls the constant linear velocity of the disc and other disc-related operations by considering frequency and the phase servo signals according to a frame synchronizing signal Sf provided from a synchronous detector
220
. The audio/video decoder
600
performs operations for sorting data output from the system decoder
200
into audio and video data to reproduce the original audio and video data recorded on the disc. The audio and video data demodulated by the audio/video decoder
600
are delivered to an NTSC (or PAL) encoder
700
and to a digital analog converter
800
, respectively, thereby being output to a monitor
960
and a speaker
970
, respectively. A ROM decoder
950
is typically built into a host (for example, a personal computer) and operated by instructions thereof, which transfers data from the system decoder
200
to the host (computer) according to a specific interface method.
Referring to
FIGS. 1 and 2
, first and second memories
330
,
280
are employed, which are static and dynamic RAMs, respectively, in which the former is used for error correction and the latter is used for data buffering. That is, data retrieved from the disc
100
is demodulated to its state prior to recording and is stored in the first memory
330
. The data stored in the first memory
330
is retrieved in units of blocks and delivered to and corrected by an error corrector
230
. The data, corrected by error corrector
230
, is then stored again in the first memory
330
. The descrambler performs descrambling with respect to the error corrected data retrieved from the first memory
330
and stores descrambled data in the second memory
280
.
The data stored in the second memory
280
is retrieved to be transferred to the audio/video decoder
600
or to the ROM decoder
950
. The audio/video decoder
600
sorts the data transmitted from the system decoder
200
into audio and video data, respectively, in order to reproduce the original audio and video data, respectively. The built-in ROM decoder
950
within the host (for example, a personal computer) is operated by instructions of the host, thereby transferring the data from the system decoder
200
to the host (computer) according to the specific interface method.
The first and second memory controllers
320
,
270
perform functions to generate addresses and to prevent over-flow and under-flow conditions, etc. for the first and second memories
280
,
330
, respectively. As mentioned above, since the conventional system decoder
200
includes separate memories for error correcting and data buffering, and accordingly, includes separate respective memory controllers, the construction of the system decoder becomes not only complicated and expensive, and also makes it difficult to miniaturize products incorporating the same.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an inexpensive and miniaturized digital video disc playback device capable of error correcting and data buffering by means of a single memory without using separate error correcting and data buffering memories.
Another object of the invention is to provide a method for using single memory in a system decoder for storing a plurality of types of data used in the system decoder.
To achieve the object of the invention there is provided a system decoder for demodulating, error correcting, deinterleaving and descrambling of data reproduced from discs in the digital video disc playback device according to the present invention comprises a memory, and a memory controller for generating addresses for recording and retrieving data by accessing the memory when demodulating, error correcting and descrambling the information reproduced from the disc.
To achieve another object of the invention, there is provided a method for decoding data reproduced from a digital video disc, used in a playback device including a main device controller and a system decoder having a memory device. The method comprises demodulating a data stream generated from data retrieved from the disc into symbols, wherein each of the symbols contains a predetermined number of bits, outputting demodulated data and storing the demodulated data in the memory device; retrieving a block of the demodulated data from the memory and performing error correction operations on the block of demodulated data to correct an error in the retrieved demodulated data and storing error corrected data which includes ID data and main data in the memory device; retrieving from the memory device and descrambling only the main data from among the error corrected data stored in the memory device, thereby restoring data originally recorded on the disc and storing descrambled data in the memory device; and retrieving from the memory device the error corrected data and detecting an error contained in the ID data of the error corrected data.


REFERENCES:
patent: 5398072 (1995-03-01), Auld
patent: 5502494 (1996-03-01), Auld
patent: 5519681 (1996-05-01), Maeda et al.
patent: 5555229 (1996-09-01), Kojima et al.
patent: 5590106 (1996-12-01), Shimizume et al.
patent: 5596558 (1997-01-01), Arataki et al.
patent: 5602812 (1997-02-01), Miura et al.
patent: 5612939 (1997-03-01), Ueki et al.
patent: 5694380 (1997-12-01), Shimizume et al.
patent: 5737415 (1998-04-01), Akiyama et al.
patent: 5751887 (1998-05-01), Nitta et al.
patent: 5793724 (1998-08-01), Ichikawa et al.
patent: 5835636 (1998-11-01), Auld

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