Wide capture range circuitry
AssigneeTexas Instruments Incorporated
InventorsKoyu Yamanoi, Hiroshi Kobayashi, Futoshi Fujinara
Life of this patent
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Abstract
Circuitry and method for synchronizing operating speeds of signal processing devices to the data rate of a signal. It applies in particular to Compact Disk (CD) and Digital Versatile Disk (DVD) drives to be used with portable devices. The circuitry does not require clock synchronization speeds in excess of the instantaneous data rate used by the disk drive and also reduces power consumption.
Claims32
A system employing a drive having a speed synchronization capacity, the synchronization capacity comprising:
- first and second signal sources generating a first and a second signal, respectively;
- a first circuit, for receiving said first and second signals in order to establish a first estimated synchronization frequency near that of an operating speed of the drive and for generating a third signal containing said first estimated frequency;
- a second circuit, for receiving said third signal in order to refine said first estimated frequency and for generating a fourth signal containing said refined estimated frequency;
- a third circuit, for receiving said fourth signal in order to establish a desired frequency of operation with a predetermined variance, and to generate a fifth signal containing said desired frequency;
- and
- a fourth circuit, for receiving said fifth signal in order to detect and lock said desired frequency as a synchronization frequency.
A method for synchronizing the operating speed of a system, comprising:
- providing reference and timing signals;
- detecting and capturing first, second and third estimates of a frequency near that of an operating speed of the drive, said third estimate having a desired center value and variance;
- identifying a desired synchronization pattern within said third estimate and generating a synchronization indication;
- and
- phase locking said synchronization indication.
A disk drive having a speed synchronization capacity, the synchronization capacity comprising:
- first and second signal sources generating a first and a second signal, respectively;
- a first circuit, for receiving said first and second signals in order to establish a first estimated synchronization frequency near that of an operating speed of the drive and for generating a third signal containing said first estimated frequency;
- a second circuit, for receiving said third signal in order to refine said first estimated frequency and for generating a fourth signal containing said refined estimated frequency;
- a third circuit, for receiving said fourth signal in order to establish a desired frequency of operation with a predetermined variance, and to generate a fifth signal containing said desired frequency;
- and
- a fourth circuit, for receiving said fifth signal in order to detect and lock said desired frequency as a synchronization frequency.
A method for synchronizing the operating speed of a disk drive, comprising:
- providing reference and timing signals;
- detecting and capturing first, second and third estimates of a frequency near that of an operating speed of the drive, said third estimate having a desired center value and variance;
- identifying a desired synchronization pattern within said third estimate and generating a synchronization indication;
- and
- phase locking said synchronization indication.
Dependencies are inferred from the claim text.