Systems and methods for low latency media defect detection
View Patent ↗Various embodiments of the present invention provide systems and methods for media defect detection. For example, a media defect detection systems is disclosed that includes a data input derived from a medium, a fast envelope calculation circuit that receives the data input and provides a fast decay envelope value based on the data input, a slow envelope calculation circuit that receives the data input and provides a slow decay envelope value based on the data input, and a media defect detection circuit. The media defect detection circuit receives the slow decay envelope value and the fast decay envelope value, calculates a ratio value of the fast decay envelope value to the slow decay envelope value, and asserts a defect output based at least in part on the comparison of the ratio value to a defect threshold value.
1. A data detection system, wherein the data detection system comprises:
an analog input signal derived from a medium;
an analog to digital converter, wherein the analog to digital converter is operable to receive the analog input signal and to provide a series of digital samples corresponding to the analog input signal;
a data detector circuit, wherein the data detector circuit is operable to perform a data detection algorithm on the digital sample to provide a detected output, and wherein the data detector circuit is operable to provide an adaptive feedback signal that indicates a difference between the digital sample and the detected output and is used to drive an adaptive feedback loop;
a media defect detector circuit, wherein the media defect detector circuit is operable to receive the digital sample, and wherein the media defect detector circuit is operable to determine whether the analog input signal is derived from a defective portion of the medium based in part on the digital sample and to assert a defect output; and
wherein the adaptive feedback loop is disabled when the defect output is asserted.
2. The data detection system of claim 1 , wherein the media defect detector circuit includes:
a fast envelope calculation circuit operable to provide a fast decay envelope value based on a media defect input derived from the series of digital samples;
a slow envelope calculation circuit operable to provide a slow decay envelope value based on the media defect input derived from the series of digital samples; and
a media defect determination circuit operable to calculate a ratio value of the fast decay envelope value and the slow decay envelope value, and wherein the defect output is asserted upon determining that the ratio value is greater than a defect threshold value.
3. The data detection system of claim 2 , wherein the system further comprises:
a moving average filter operable to receive one of the series of digital samples and to calculate a moving average value based on the one of the series of digital samples and one or more preceding digital samples, and to subtract the moving average value from the one of the series of digital samples to yield the media defect input.
4. The data detection system of claim 2 , wherein the defect threshold value is programmable.
5. The data detection system of claim 1 , wherein the medium is a magnetic storage medium.
6. The data detection system of claim 1 , wherein the medium is a wireless communication medium.
7. The data detection system of claim 1 , wherein the data detection system is implemented as part of an integrated circuit.
8. A data detection system, wherein the data detection system comprises:
a data detector circuit operable to apply a data detection algorithm to a detector input derived from a medium to yield a detected output, and to provide an adaptive feedback signal indicating a difference between the detector input and the detected output, wherein the adaptive feedback signal is used to drive an adaptive feedback loop;
a media defect detector circuit operable to determine whether the detector input is derived from a defective region of the storage medium based at least in part on the detector input, and to assert a defect output where it is determined that the detector input is derived from a defective region; and
wherein the adaptive feedback loop is disabled when the defect output is asserted.
9. The data detection system of claim 8 , wherein the data detection system further comprises:
an analog to digital converter operable to convert an analog input signal derived from the medium to yield a series of digital samples, wherein the detector input is derived from the series of digital samples.
10. The data detection system of claim 9 , wherein the media defect detector circuit includes:
a fast envelope calculation circuit operable to provide a fast decay envelope value based on a media defect input derived from the series of digital samples;
a slow envelope calculation circuit operable to provide a slow decay envelope value based on the media defect input derived from the series of digital samples; and
a media defect determination circuit operable to calculate a ratio value of the fast decay envelope value and the slow decay envelope value, and wherein the defect output is asserted upon determining that the ratio value is greater than a defect threshold value.
11. The data detection system of claim 10 , wherein the system further comprises:
a moving average filter operable to receive one of the series of digital samples and to calculate a moving average value based on the one of the series of digital samples and one or more preceding digital samples, and to subtract the moving average value from the one of the series of digital samples to yield the media defect input.
12. The data detection system of claim 8 , wherein the medium is a magnetic storage medium.
13. The data detection system of claim 12 , wherein the data detection system further comprises:
a read write head assembly disposed in relation to the magnetic storage medium and operable to provide a sensed signal corresponding to information maintained on the magnetic storage medium;
an analog front end circuit operable to convert the sensed signal to a processed analog output; and
an analog to digital converter operable to convert the processed analog output to yield a series of digital samples, wherein the detector input is derived from the series of digital samples.
14. The data detection system of claim 8 , wherein the medium is a wireless communication medium.
15. The data detection system of claim 14 , wherein the system further includes:
an analog front end circuit operable to sense a radio frequency signal from the wireless communication medium and to produce an analog output; and
an analog to digital converter operable to convert the processed analog output to yield a series of digital samples, wherein the detector input is derived from the series of digital samples.
16. The data detection system of claim 8 , wherein the data detection system is implemented as part of an integrated circuit.