| 摘要 |
A method and apparatus are disclosed for detecting an address mark in a data stream having a preamble followed by the address mark. The end of the preamble is detected in the data stream, which is then used to open a window to search for the address mark. If the address mark is not detected during the window, the search for the address mark is restarted. The window can have a duration based on a length of the address mark. The address mark can be, for example, a servo address mark following a servo preamble or a read address mark following a read preamble. The preamble can have a 2T pattern and the preamble can be detected by determining if energy associated with a 2T frequency is greater than energy associated with a non-2T frequency. The end of the preamble can be performed by an EndOf2T detector that detects a break in an expected bit pattern. |
