摘要:
A system and method for processing track identifier errors to mitigate head instability in data storage devices is disclosed. The system and method includes computing a track id differential between an expected track id and a received track id, encoding the expected track id and the received track id, initiating a first action if the track id differential exceeds a pre-determined threshold and the encoded expected track id varies from the encoded received track id by a pre-configured number of bits, and initiating a second action if the track id differential does not exceed the pre-determined threshold or the encoded expected track id does not vary from the encoded received track id by a pre-configured number of bits.
摘要:
A magnetic disk drive having a reduction in repeatable runout (RRO) effects is disclosed. The disk drive has a head disk assembly (HDA) and a sampled servo controller. The HDA includes a rotating magnetic disk, an actuator, and a transducer head. The magnetic disk has a plurality of embedded servo sectors for storing servo information including repeatable runout (RRO) cancellation values and RRO cancellation value error correction code (ECC) data at a servo data rate. The RRO cancellation value ECC data is only for detecting and correcting errors in the RRO cancellation values. In between the embedded servo sectors are data sectors for storing user data at a user data rate that is different from the servo data rate. The actuator positions the transducer head in response to a control effort signal generated by the sampled servo controller based on the servo information.
摘要:
A head gimbal assembly for a disk drive. The head gimbal assembly includes a trace suspension assembly backing layer including a gimbal. The trace suspension assembly backing layer is formed of a conductive material having a first oxidation rate. The head gimbal assembly further includes a gimbal conductive layer disposed upon the gimbal and formed of a conductive material having a second oxidation rate lower than the first oxidation rate. The head gimbal assembly further includes a slider supported by the gimbal. The head gimbal assembly further includes a conductive compound disposed between the gimbal conductive layer and the slider for electrically grounding the slider to the trace suspension assembly backing layer.
摘要:
A Head Gimbal Assembly (HGA) for use in a disk drive and comprising an ESD-protected slider comprising a head formed on a slider substrate. The slider may comprise an electrical-isolation circuit; an electrically-resistive path between head input connections and the slider; or both isolation circuits and resistive paths for reducing electrostatic charge on the slider while remaining connected during disk drive operations.
摘要:
A Head Gimbal Assembly (HGA) for use in a disk drive and further includes a head having a read element and a write element; and a Trace Gimbal Assembly (TGA) attached to the head. The TGA includes a conductor array having a first end connected to the read element and the write element and a distal end for connecting the read element and the write element to a signal processing circuit, a conductive substrate supporting the head and the conductor array and a dielectric layer disposed between the conductor array and the conductive substrate. The TGA further includes a shunt connected at the distal end for shunting the read element; and an anti-static coating, covering a substantial portion of the conductor array for neutralizing electrostatic charge accumulation on the conductor array.
摘要:
In an OFDM system, multiple (M) interlaces are defined for M non-overlapping sets of frequency subbands, and M slots with fixed indices are also defined. Data streams and pilot are mapped to slots, which are in turn mapped to interlaces based on a slot-to-interlace mapping scheme that can achieve frequency diversity and good performance for all slots. At a transmitter, a slot-to-interlace converter maps the slots to the interlaces. The slot-to-interlace converter includes multiple multiplexers and a control unit. The multiplexers map the M slots to the M interlaces based on the slot-to-interlace mapping scheme. The control unit generates at least one control signal for the multiplexers. The multiplexers may be arranged and controlled in various manners depending on the slot-to-interlace mapping scheme. At a receiver, a complementary interlace-to-slot converter maps the interlaces to the slots.
摘要:
Techniques for performing IFFT pipelining are described. In some aspects, the pipelining is achieved with a processing system having a memory having first and second sections, an encoder configured to process data in each of the first and second memory sections, an IFFT configured to process the encoded data in the first and second memory sections, and a post-processor configured to process the IFFT processed data in the first memory section while the IFFT is processing the encoded data in the second memory section, the post processor configured to operate at a different clock speed than the encoder or the IFFT.
摘要:
A head stack assembly includes a flex cable assembly. The head stack assembly further includes an actuator arm and a load beam coupled to the actuator arm. The head stack assembly further includes a trace suspension assembly backing layer coupled to the load beam and including a gimbal. The head stack assembly further includes a dielectric layer disposed upon the trace suspension assembly backing layer. The head stack assembly further includes a slider supported by the gimbal. The head stack assembly further includes a ground trace disposed upon the dielectric layer with the dielectric layer between the ground trace and the trace suspension assembly backing layer. The ground trace extends along the actuator arm and is electrically connected to the slider and the flex cable assembly for grounding the slider to the flex cable assembly.
摘要:
The present invention may be embodied in a disk drive comprising a rotating magnetic media having tracks identified by binary codewords, and in a related method. Each track codeword for a particular track within a contiguous band of tracks differs from a track codeword for an adjacent track within the contiguous band of tracks by a defined number of bits, and differs from a track codeword for a nonadjacent track within the contiguous band of tracks by at least the defined number of bits. The defined number N of bits is greater than four such that at least two bit errors may be corrected when reading a track codeword.
摘要:
A system and method for processing track identification data in a disk drive having concentric tracks each having a track identification field (TIF) stored in embedded servo sectors, the TIF includes a band segment identifying a group of tracks, and an index segment identifying a single track of the group of tracks. The system and method include reading a servo sector to obtain the TIF, parsing the TIF to obtain the band segment, comparing the obtained band segment to an expected band segment to obtain a band segment differential (BSD), initiating an action if the BSD exceeds a pre-determined threshold and varies from the expected band segment by a predetermined number of bits, initiating another action if the BSD exceeds the predetermined threshold and does not vary from the expected band segment by the predetermined number of bits. The process is then applied to the index segments of the band segment.