Abstract: Apparatuses and methods for utilizing error correction code in a data buffer or data storage device. In one variation, a single memory device is utilized to store both the data and the associated error correction code. The data and the associate error correction codes are stored on separate memory banks on the memory device. The error correction code may be consolidated into one or more regions on the memory device to improve the utilization of the available memory space on the memory device. In addition, by utilizing separate memory banks to store the data and the associated error correction code, the data and the error correction code can be accessed in an overlapping manner.

Abstract: An automatic velocity calibrator for a head positioning servo system in a magnetic disk drive performs a velocity calibration in a single pass over the magnetic disks by measuring actuator velocity and adjusting the gain of the velocity transducer in a series of successive approximations. Velocity is determined by turning a timer on in response to a track crossing and turning the timer off after at least two successive track crossings have been detected. A plurality of velocity measurements are stored and averaged. The average velocity is compared to a constant velocity command and an 8-bit latch is incremented or decremented in response to this comparison. A digital to analog converter produces a reference for an automatic gain control amplifier in the servo system which in turn adjusts the velocity transducer gain.