摘要:
A system for halting operation of a hard disk controller when a write operation occurs during a servo positioning error condition including a memory cell for retaining an indication of whether a write operation occurred during the previous servo sector. A memory cell, such as a flip flop, is set on any occurrence of a write operation. With the reading of a next servo field, the output of the first flip flop is latched to a second flip flop. During a present servo sector, a servo positioning error signal is logically AND'ed with a write gate active signal where the write gate active signal is enabled if write gate is active in the present servo sector or write gate was active in the previous servo sector (as indicated by the output from the second flip flop.
摘要:
A disk drive is disclosed comprising a head actuated over a disk, a first volatile semiconductor memory (VSM), and a second VSM. When the disk drive is powered on, control circuitry first reads VSM initialization code from the disk, first initializes the first VSM using the VSM initialization code, stores the VSM initialization code in the second VSM, and then enters a power save mode. When exiting the power save mode, the control circuitry second initializes the first VSM using the VSM initialization code stored in the second VSM.