Amplitude spike detector for head instability

摘要

A hard disk drive that contains a self-test for generating data on head spikes. The data is stored on a system track of the drive. The self-test may be firmware embedded into a memory device of the drive. The self-test automatically runs when power is provided to the drive. This allows for a 100% spike detection test for disk drives assembled at a manufacturing facility. The self-test includes writing a test waveform, reading the test waveform and comparing the read waveform with a threshold to determine the existence of spikes. Data on the spikes is then stored on the system track. The data is compared with certain criteria to determine whether the disk drive is defective.