Reference clock generating circuit of disk data burst...

Details Reference clock generating circuit of disk data burst... Reference clock generating circuit of disk data burst...

2000-11-21

2003-09-09

Tran, Thang V. (Department: 2653)

Dynamic information storage or retrieval

Control of storage or retrieval operation by a control...

Mechanism control by the control signal

C369S047410

Reexamination Certificate

active

06618333

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a reference clock generating circuit for a burst cutting area (BCA), and especially to for a reference clock generating circuit, by which a reference clock of a spindle control circuit can be divided to acquire a BCA reference clock.
BACKGROUND OF THE INVENTION
Since the photoelectric technology is improved greatly, a high quality image and audio effect can be acquired through a digital video and audio technology. The digital versatile disk is widely used recently. In the manufacturing of the digital versatile disk, a burst cutting area (BCA) is formed near the center round hole of the disk, referring to FIG.
1
. In
FIG. 1
, a center hole is formed in the center of a disk
1
. The periphery of the center hole
2
is with a burst cutting area (BCA)
3
for recording special information of the disk. Referring to
FIG. 2
, the special information in the burst cutting area of the disk illustrated in
FIG. 1
is illustrated. (If low level is defined as 1 bit, then a period T can be used to store a plurality of 0 bits, while the 0 bit represent different section
1
,
3
,
5
etc., stores with different contents).
However, currently, the system clock in the controlling chip set is applied as a BCA reference clock for reading BCA data. With reference to
FIG. 3
, a BCA reference clock (BCAREFCLK) of the current system clock is illustrated, which is employed to acquire the BCA data.
FIG. 3
illustrates a control chip of a DVD-ROM drive. The system clock generator
6
receivers an output frequency from an oscillator
5
. Afterwards, the system clock generator
6
outputs a BCA reference clock (BCAREFCLK).
However, in this conventional method, user must refer the rotary speed of the spindle motor, and monitors the system clock correspondent to the rotary speed of the motor for processing the BCA data. Namely, the user must perform the transformation operation of current rotary speed and BCA channel bit cycle for reading the BCA data. When the rotary speed of the spindle motor increases, the system clock also increases, therefore, a big trouble is induced as the user programs a BCA reference clock register.
SUMMARY OF THE INVENTION
Accordingly, the primary object of the present invention is to provide a BCA reference clock generating circuit of a DVD drive from the reference clock of a spindle control circuit. Besides, a BCA clock and BCA data is generated from the BCA reference clock. Therefore, through a varied reference clock, the BCA data of a digital video disk is read stably without considering the rotary speed of the spindle motor.
Therefore, the reference clock outputted from the spindle control circuit can be varied with the rotary speed of the spindle motor, (and the channel bit of the BCA is a fixed reference clock cycle), so that the user is unnecessary to perform the transformation operation between the current rotary speed and the BCA channel bit cycle.
To achieve the above objects, the present invention a reference clock generating circuit for a disk data burst cutting area (BCA) comprising a reference clock being an original reference clock employed in a spindle control circuit; a plurality of dividers being connected in series for receiving signals of the reference clock; after the reference clock is divided in different dividers, a BCA reference clock being generated; a spindle control circuit structure to a last output of the plurality of dividers for generating signals for being inputted to a motor, thereby, the motor rotating in a forward or a backward direction or stopping; and a Hall sensor for receiving a Hall sensor impulse signal; after the impulse is processed by the Hall sensor, a disk rotary frequency (FODR) being generated; and then the frequency being transferred to the spindle control circuit.
The reference clock signal is outputted from one of the plurality of dividers as a reference clock of a BCA data in a digital video disk (DVD). As a result, in a read mode, the BCA is unnecessary to refer to rotary speed of the spindle motor, and thus it is a clock signal varied with variation of the rotary speed.
Preferably, the BCA reference clock from the reference clock is divided by the dividers is further processed by a BCA data slicer for generating a BCA data and then is transferred to a BCA clock extractor for reading the BCA data in a digital video disk.
Moreover, the serial connected dividers include a first divider, a second divider and a third divider, which are connected in series.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.


REFERENCES:
patent: 5089757 (1992-02-01), Wilson
patent: 5315571 (1994-05-01), Maeda et al.
patent: 5377178 (1994-12-01), Saito et al.
patent: 6538965 (2003-03-01), Mochizuki et al.

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