Seagate Technology Incorporated

Jpmorgan Chase Bank, As Collateral Agent

QuekLeong Choo

Myint Ngwe

WeiMing Yeow

KianWai Ng

Wenxiang Xie

Jian Qiang

Choon Wei Ng

WeiLoon Ng

KokHoe Chia

CheeWai Lum

TeckKhoon Lim

FongKheon Chong

SanYuan Liew

EngHock Lim

CheeWee Cheng

HiauChoon Kee

KahLiang Gan

The disclosed technology provides a system and method that improves command completion time in a shingled magnetic recording device system. In one implementation, the system and method include receiving a write command to write data to a first track in a band in a recording medium, seeking to a first track, reducing an on-cylinder limit (OCLIM) from a default OCLIM to a reduced OCLIM by a predetermined amount on the first track, performing write operations on the first track with the reduced OCLIM, and determining if a transfer of data to the first track band in the write operations has been substantially completed. Upon determining that a transfer of data to the first track in the write operations has been substantially completed, the OCLIM is restored from a reduced OCLIM to a default OCLIM and write operations are performed on tracks adjacent to the first track.

Shingled magnetic recording storage system improving command completion time

Methods and associated apparatus to reduce electrical power consumption in an information channel may include identifying times at which to restore power to elements in the information channel, and restoring power to the elements at the identified times. Times for each element are identified based on a recovery time for that element to reach a sufficiently stable operating point before a transition to an active mode of operation. By maximizing the length of time individual elements may stay in the reduced power mode, power savings may be maximized without negatively affecting information channel performance.

Power management in an information channel

Embodiments of the present invention include a method and an apparatus for generating an optimal MRO for a zone having a plurality of tracks. A disc drive controller determines the optimum MRO of a zone of tracks by analyzing multiple tracks in the zone with the actuator arm located at a series of offsets relative to the track center. Selected tracks in the zone are written to once. Then the selected tracks in the zone are sequentially read at a first offset, and the corresponding errors recorded. This reading is repeated for each of the offsets until all offsets have been analyzed. Based on the offset, or band of offsets, with the least errors over the selected tracks, the optimum MRO can be selected for the zone. The process can be repeated for each zone and the optimum MRO values stored in an MRO table in the disc drive for use during subsequent read and write operations.

Multi-tracks MR offset tuning based on error count in certification process

According to one embodiment of the present invention, a method of tuning a Power-On-Reset (POR) register in a data storage device comprises determining a tuned value for the POR register using feedback from the data storage device obtained during a certification process of the data storage device and storing a list in one or more system sectors of the data storage device, the list comprising an address of the POR register to be patched and the tuned value. According to another embodiment of the present invention, a disc drive comprises a rotatable disc, a microprocessor, and a memory. The memory has a start-up routine that, when executed by the microprocessor, causes the microprocessor to patch a Power-On-Reset (POR) register using a tuned values stored in one or more system sectors of the rotatable disc.

Dynamic mask-ROM register patching

An apparatus and associated method for detecting head collision with disc media, or other matter, during a write operation is disclosed. The method and apparatus generally monitor the resistance of an MR element on the head in order to detect a temperature increases indicative of a head collision. The resistance can be compared to a pre-selected threshold to generate an output indicative of head collision.

Write head collision detection using MR read element in disc drives

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Singapore, Singapore

QuekLeong Choo