Western Digital Technologies, Inc.

Travis E Ell

Raffi Codilian

Hanan Kupferman

Teik Ee Yeo

Jonathan V Nguyen

Saied Tamaddon-Dallal

Hoa V Le

Virat Thantrakul

Disclosed is a disk drive having a disk, a masked read-only memory (ROM) device, a reprogrammable nonvolatile memory device, and a microprocessor for executing program code. The disk has a magnetic data storage surface with embedded servo wedges for defining data storage tracks including reserve tracks. The masked ROM device stores program code for implementing a spindle motor controller, program code for implementing a portion of a servo controller for track following along a data storage track, and program code for implementing a portion of a disk controller for controlling writing disk data to and reading disk data from the reserve tracks. The reprogrammable nonvolatile memory device stores data parameters relating to the disk drive's configuration. The reserve tracks store program code for implementing a cache control system for controlling caching of disk data in a cache memory.

Disk drive and method having cost-effective storage of the disk drive's internal program code

Disclosed is a control system for processing sampled servo data in a disk drive. The control system includes a microprocessor and a servo processing accelerator circuit for performing operations on the sampled servo data while the microprocessor is executing firmware code. The accelerator circuit supports the use of a higher servo bandwidth thus allowing a higher track density resulting a greater storage capacity for the disk drive. Also, the accelerator circuit relieves the microprocessor of the ordinary servo processing function. Thus, the microprocessor's limited processing capacity to be directed to other controller and interface functions of the disk drive. Only under unusual conditions, such as a write-unsafe (WUS) limit exception, does the microprocessor need to direct processing capacity to the servo processing function. Further, the accelerator circuit may be a decreased response time after reading the servo data from the disk.

Disk drive control system having a servo processing accelerator circuit

Growing community of inventors

Foothill Ranch, CA, United States of America

Travis E Ell