Data storage device demodulating servo burst by computing slope of intermediate integration points
AssigneeWestern Digital Technologies, Inc.
InventorsShan Tang, Zhenyu Zhang, Chuanwen Ji, Duc T. Phan
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Abstract
A data storage device is disclosed comprising a head actuated over a disk surface comprising tracks defined by servo sectors, wherein each servo sector comprises at least one servo burst comprising a periodic pattern. The servo burst of one of the servo sectors is read to generate a read signal, and M intermediate integration points yNi are computed according to: y N i = ∑ k = 0 N i r ( k T s ) · sin ( ω k T s ) ; i = 0 , 1 , … , M - 1 where r(kTs) represents a sample point of the read signal, Ts represents a sample interval between the sample points, and ω represents a frequency of the periodic pattern in the servo burst.
Claims22
A data storage device comprising:
- a disk surface comprising tracks defined by servo sectors, wherein each servo sector comprises at least one servo burst comprising a periodic pattern;
- a head actuated over the disk surface;
- and
- control circuitry configured to:
- read the servo burst of one of the servo sectors to generate a read signal;
- and
- compute M intermediate integration points yNi according to:
- y
- N
- i
- =
- ∑
- k
- =
- 0
- N
- i
-
- r
-
- (
- k
-
-
- T
- s
- )
- ·
- sin
-
- (
- ω
-
-
- k
-
-
- T
- s
- )
- ;
- i
- =
- 0
- ,
- 1
- ,
- …
-
- ,
- M
- -
- 1
- where:
- r(kTs) represents a sample point of the read signal;
- Ts represents a sample interval between the sample points;
- and
- ω represents a frequency of the periodic pattern in the servo burst.
A method of operating a data storage device, the method comprising:
- reading a periodic pattern in a servo burst of a servo sector on a disk surface to generate a read signal;
- and
- computing M intermediate integration points yNi according to:
- y
- N
- i
- =
- ∑
- k
- =
- 0
- N
- i
-
- r
-
- (
- kT
- s
- )
- ·
- sin
-
- (
- ω
-
-
- kT
- s
- )
- ;
- i
- =
- 0
- ,
- 1
- ,
- …
-
- ,
- M
- -
- 1
- where:
- r(kTs) represents a sample point of the read signal;
- Ts represents a sample interval between the sample points;
- and
- ω represents a frequency of the periodic pattern in the servo burst.
Dependencies are inferred from the claim text.