Granted Patent B2

US 7,595,951 · App. 11/445,535 · Granted Sep 29, 2009

Abstract

Claims (159)

1. A recording system for writing incoming data to and reading outgoing data from a recording medium, the system comprising:

a write head adapted to generate an electromagnetic (EM) field based on the incoming data for writing to the recording medium;

a read head adapted to sense an EM field corresponding to the outgoing data for reading from the recording medium;

writer circuitry adapted to amplify incoming signals corresponding to the incoming data for application to the write head;

reader circuitry adapted to amplify outgoing signals generated by the read head corresponding to the outgoing data; and

a controller adapted to control operations of the writer circuitry and the reader circuitry, wherein:

first circuitry being one of the writer circuitry and the reader circuitry supports (1) a low-power mode in which said first circuitry is powered at a low power level, (2) an intermediate-power mode in which said first circuitry is powered at an intermediate power level, and (3) a full-power mode in which said first circuitry is powered at a full power level;

if said first circuitry is the writer circuitry, then second circuitry is the reader circuitry, and vice versa;

during a full-power operation of said second circuitry, said first circuitry is adapted to be in either the low-power mode or the intermediate-power mode, as selected by the controller; and

the controller is adapted to:

transition said first circuitry to the low-power mode at the beginning of the full-power operation of said second circuitry; and

transition said first circuitry to the intermediate-power mode at the end of the full-power operation of said second circuitry.

2. The recording system of claim 1 , wherein the writer circuitry and the reader circuitry are part of a preamplifier of the system.

3. The recording system of claim 1 , wherein:

said first circuitry is the reader circuitry;

the low-power mode is a reader standby mode in which the reader circuitry is powered at the low power level;

the intermediate-power mode is a pre-read mode in which the reader circuitry is powered at the intermediate power level;

the full-power mode is a read mode in which the reader circuitry is powered at the full power level; and

the reader circuitry is adapted to be in either the reader standby mode or the pre-read mode during a full-power write operation of the writer circuitry.

4. The recording system of claim 3 , wherein:

the reader circuitry comprises a dummy head;

during the read mode, the reader circuitry applies a read bias current to the read head;

during the pre-read mode, the reader circuitry applies the read bias current to the dummy head; and

during the reader standby mode, the reader circuitry does not generate any significant read bias current.

5. The recording system of claim 3 , wherein the controller is adapted to:

transition the reader circuitry to the reader standby mode at the beginning of the full-power write operation of the writer circuitry; and

transition the reader circuitry to the pre-read mode at the end of the full-power write operation of the writer circuitry.

6. The recording system of claim 1 , wherein:

said first circuitry is the writer circuitry;

the low-power mode is a writer standby mode in which the writer circuitry is powered at the low power level;

the intermediate-power mode is a pre-write mode in which the writer circuitry is powered at the intermediate power level;

the full-power mode is a write mode in which the writer circuitry is powered at the full power level; and

the writer circuitry is adapted to be in either the writer standby mode or the pre-write mode during a full-power read operation of the reader circuitry.

7. The recording system of claim 6 , wherein the controller is adapted to:

transition the writer circuitry to the writer standby mode at the beginning of the full-power read operation of the reader circuitry; and

transition the writer circuitry to the pre-write mode at the end of the full-power read operation of the reader circuitry.

8. The recording system of claim 1 , wherein the controller is adapted to transmit a lookahead control signal to said first circuitry to cause said first circuitry to transition from the low-power standby mode to the intermediate-power mode prior to the end of the full-power operation of said second circuitry.

9. The recording system of claim 8 , wherein the lookahead control signal is time-multiplexed with another signal transmitted between the controller and said first circuitry.

10. The recording system of claim 1 , wherein:

the writer circuitry and the reader circuitry are part of a preamplifier of the system;

said first circuitry is the reader circuitry;

the low-power mode is a reader standby mode in which the reader circuitry is powered at the low power level;

the intermediate-power mode is a pre-read mode in which the reader circuitry is powered at the intermediate power level;

the full-power mode is a read mode in which the reader circuitry is powered at the full power level;

the reader circuitry is adapted to be in either the reader standby mode or the pre-read mode during a full-power write operation of the writer circuitry;

the reader circuitry comprises a dummy head;

during the read mode, the reader circuitry applies a read bias current to the read head;

during the pre-read mode, the reader circuitry applies the read bias current to the dummy head;

during the reader standby mode, the reader circuitry does not generate any significant read bias current;

the controller is adapted to:

transition the reader circuitry to the reader standby mode at the beginning of the full-power write operation of the writer circuitry; and

transition the reader circuitry to the pre-read mode at the end of the full-power write operation of the writer circuitry; and

the controller is adapted to transmit a reader lookahead control signal to the reader circuitry to cause the reader circuitry to transition from the low-power reader standby mode to the intermediate-power pre-read mode prior to the end of the full-power write operation of the writer circuitry.

11. The recording system of claim 10 , wherein the lookahead control signal is time-multiplexed with another signal transmitted between the controller and said first circuitry.

12. The recording system of claim 10 , wherein:

the writer circuitry has (1) a low-power writer standby mode in which the writer circuitry is powered at a low power level, (2) an intermediate-power pre-write mode in which the writer circuitry is powered at an intermediate power level, and (3) a full-power write mode in which the writer circuitry is powered at a full power level;

the writer circuitry is adapted to be in either the writer standby mode or the pre-write mode during a full-power read operation of the reader circuitry;

the controller is adapted to:

transition the writer circuitry to the writer standby mode at the beginning of the full-power read operation of the reader circuitry; and

transition the writer circuitry to the pre-write mode at the end of the full-power read operation of the reader circuitry; and

the controller is adapted to transmit a writer lookahead control signal to the writer circuitry to cause the writer circuitry to transition from the low-power writer standby mode to the intermediate-power pre-write mode prior to the end of the full-power read operation of the reader circuitry.

13. The recording system of claim 1 , further comprising a timer adapted to be used to determine when to transition said first circuitry from the low-power standby mode to the intermediate-power mode prior to the end of the full-power operation of said second circuitry.

14. A controller for a recording system for writing incoming data to and reading outgoing data from a recording medium, the system further comprising:

a write head adapted to generate an EM field based on the incoming data for writing to the recording medium;

a read head adapted to sense an EM field corresponding to the outgoing data for reading from the recording medium;

writer circuitry adapted to amplify incoming signals corresponding to the incoming data for application to the write head; and

reader circuitry adapted to amplify outgoing signals generated by the read head corresponding to the outgoing data, wherein:

the controller is adapted to control operations of the writer circuitry and the reader circuitry;

first circuitry being one of the writer circuitry and the reader circuitry supports (1) a low-power mode in which said first circuitry is powered at a low power level, (2) an intermediate-power mode in which said first circuitry is powered at an intermediate power level, and (3) a full-power mode in which said first circuitry is powered at a full power level;

if said first circuitry is the writer circuitry, then second circuitry is the reader circuitry, and vice versa;

during a full-power operation of said second circuitry, said first circuitry is adapted to be in either the low-power mode or the intermediate-power mode, as selected by the controller; and

the controller is adapted to:

transition said first circuitry to the low-power mode at the beginning of the full-power operation of said second circuitry; and

transition said first circuitry to the intermediate-power mode at the end of the full-power operation of said second circuitry.

15. Writer circuitry for a recording system for writing incoming data to and reading outgoing data from a recording medium, the system further comprising:

a write head adapted to generate an EM field based on the incoming data for writing to the recording medium;

a read head adapted to sense an EM field corresponding to the outgoing data for reading from the recording medium;

reader circuitry adapted to amplify outgoing signals generated by the read head corresponding to the outgoing data; and

a controller adapted to control operations of the writer circuitry and the reader circuitry, wherein:

the writer circuitry supports (1) a low-power mode in which the writer circuitry is powered at a low power level, (2) an intermediate-power mode in which the writer circuitry is powered at an intermediate power level, and (3) a full-power mode in which the writer circuitry is powered at a full power level;

during a full-power read operation of the reader circuitry, the writer circuitry is adapted to be in either the low-power mode or the intermediate-power mode, as selected by the controller; and

the writer circuitry is adapted to:

transition to the low-power mode at the beginning of the full-power read operation of the reader circuitry; and

transition to the intermediate-power mode at the end of the full-power read operation of the reader circuitry.

16. The writer circuitry of claim 15 , wherein:

the writer circuitry is part of a preamplifier of the system; and

the preamplifier further comprises the reader circuitry.

17. Reader circuitry for a recording system for writing incoming data to and reading outgoing data from a recording medium, the system further comprising:

a write head adapted to generate an EM field based on the incoming data for writing to the recording medium;

a read head adapted to sense an EM field corresponding to the outgoing data for reading from the recording medium;

writer circuitry adapted to amplify incoming signals corresponding to the incoming data for application to the write head; and

a controller adapted to control operations of the writer circuitry and the reader circuitry, wherein:

the reader circuitry supports (1) a low-power mode in which the reader circuitry is powered at a low power level, (2) an intermediate-power mode in which the reader circuitry is powered at an intermediate power level, and (3) a full-power mode in which the reader circuitry is powered at a full power level;

during a full-power write operation of the writer circuitry, the reader circuitry is adapted to be in either the low-power mode or the intermediate-power mode, as selected by the controller; and

the reader circuitry is adapted to:

transition to the low-power mode at the beginning of the full-power write operation of the writer circuitry; and

transition to the intermediate-power mode at the end of the full-power write operation of the writer circuitry.

18. The reader circuitry of claim 17 , wherein:

the reader circuitry is part of a preamplifier of the system; and

the preamplifier further comprises the writer circuitry.

19. A method for operating a recording system comprising:

a write head adapted to generate an electromagnetic (EM) field based on the incoming data for writing to the recording medium;

a read head adapted to sense an EM field corresponding to the outgoing data for reading from the recording medium;

writer circuitry adapted to amplify incoming signals corresponding to the incoming data for application to the write head;

reader circuitry adapted to amplify outgoing signals generated by the read head corresponding to the outgoing data; and

a controller adapted to control operations of the writer circuitry and the reader circuitry, wherein:

first circuitry being one of the writer circuitry and the reader circuitry supports (1) a low-power mode in which said first circuitry is powered at a low power level, (2) an intermediate-power mode in which said first circuitry is powered at an intermediate power level, and (3) a full-power mode in which said first circuitry is powered at a full power level; and

if said first circuitry is the writer circuitry, then second circuitry is the reader circuitry, and vice versa, the method comprising:

controlling said first circuitry to be in either the low-power mode or the intermediate-power mode, as selected by the controller, during a full-power operation of said second circuitry, wherein the controller:

transitions said first circuitry to the low-power mode at the beginning of the full-power operation of said second circuitry; and

transitions said first circuitry to the intermediate-power mode at the end of the full-power operation of said second circuitry.

20. The method of claim 19 , wherein:

said first circuitry is the reader circuitry;

the low-power mode is a reader standby mode in which the reader circuitry is powered at the low power level;

the intermediate-power mode is a pre-read mode in which the reader circuitry is powered at the intermediate power level;

the full-power mode is a read mode in which the reader circuitry is powered at the full power level; and

the reader circuitry is controlled to be in either the reader standby mode or the pre-read mode during a full-power write operation of the writer circuitry.

21. The method of claim 20 , wherein:

the reader circuitry comprises a dummy head;

during the read mode, the reader circuitry applies a read bias current to the read head;

during the pre-read mode, the reader circuitry applies the read bias current to the dummy head; and

during the reader standby mode, the reader circuitry does not generate any significant read bias current.

22. The method of claim 20 , wherein the controller:

transitions the reader circuitry to the reader standby mode at the beginning of the full-power write operation of the writer circuitry; and

transitions the reader circuitry to the pre-read mode at the end of the full-power write operation of the writer circuitry.

23. The method of claim 19 , wherein:

said first circuitry is the writer circuitry;

the low-power mode is a writer standby mode in which the writer circuitry is powered at the low power level;

the intermediate-power mode is a pre-write mode in which the writer circuitry is powered at the intermediate power level;

the full-power mode is a write mode in which the writer circuitry is powered at the full power level; and

the writer circuitry is controlled to be in either the writer standby mode or the pre-write mode during a full-power read operation of the reader circuitry.

24. The method of claim 23 , wherein the controller:

transitions the writer circuitry to the writer standby mode at the beginning of the full-power read operation of the reader circuitry; and

transitions the writer circuitry to the pre-write mode at the end of the full-power read operation of the reader circuitry.

25. The method of claim 19 , wherein the controller transmits a lookahead control signal to said first circuitry to cause said first circuitry to transition from the low-power standby mode to the intermediate-power mode prior to the end of the full-power operation of said second circuitry.

26. A method for operating a recording system having reader circuitry and writer circuitry, the method comprising:

(a) configuring one of the reader and writer circuitry for full-power operation;

(b) configuring the other circuitry into a low-power mode during a first interval of the full-power operation of the one circuitry;

(c) configuring the other circuitry into an intermediate-power mode during a second interval of the full-power operation of the one circuitry subsequent to the first interval;

(d) transitioning the one circuitry from the full-power operation to a non-full-power operation; and

(e) configuring the other circuitry into a full-power mode at the end of the full-power operation of the one circuitry.

27. The method of claim 26 , wherein:

the one circuitry is the writer circuitry;

the other circuitry is the reader circuitry;

the low-power mode is a reader standby mode;

the intermediate-power mode is a pre-read mode;

the full-power mode is a read mode;

step (a) comprises configuring the writer circuitry into a full-power write mode;

step (d) comprises transitioning the writer circuitry from the full-power write mode to a mode other than the full-power write mode; and

step (e) comprises configuring the reader circuitry into the read mode at the end of the full-power write mode of the writer circuitry.

28. The method of claim 26 , wherein:

the one circuitry is the reader circuitry;

the other circuitry is the writer circuitry;

the low-power mode is a writer standby mode;

the intermediate-power mode is a pre-write mode;

the full-power mode is a write mode;

step (a) comprises configuring the reader circuitry into a full-power read mode;

step (d) comprises transitioning the reader circuitry from the full-power read mode to a mode other than the full-power read mode; and

step (e) comprises configuring the writer circuitry into the write mode at the end of the full-power read mode of the reader circuitry.

Assignments (9)