|
September 1996, vol.13, no. 6
|
 
Access TI's on-line technical documentation.
|
 Seagate picks TI cDSPOne of the world's largest hard disk drive makers has chosen a customizable digital signal processor core from Texas Instruments to serve as the sole processor in a new product offering.Seagate Technology's 2.5 gigabyte ST52520A hard disk drive is the first mainstream 3.5-inch HDD to adopt a uniprocessor DSP design integrating logic, flash memory and a DSP core -- the T320C2xLP -- into a single unit. This highly integrated TI cDSP™ solution enabled Seagate to establish high-performance, cost effective HDD units by improving system performance, reducing power consumption and decreasing chip count."TI DSPs already provide the core processing muscle for many of our high end drives," said Edward Caragliano, vice president of VLSI Development Engineering at Seagate. "However, it is TI's ability to quickly and easily customize around a DSP core that lets us create precisely the collective solution we need to respond to our customers' demands for cost-effective higher capacities." As optimized number crunchers, the DSPs are ideal for executing the complex positioning algorithms that quickly and accurately move a HDD's read/write head to the appropriate data track for data storage or retrieval. In the application at Seagate, the T320C2xLP DSP core not only performs the servo function, but also the host-interface controller task in less time, and with much better overall performance than the microcontrollers that were used in past designs. In the past, two processors were used, one to perform each of these tasks. The program code to perform this servo control function is typically stored in a nonvolatile memory device such as ROM (read-only memory) or flash memory. Flash memory blends the nonvolatile permanence and low cost of ROM with the risk-reduced flexibility of RAM to facilitate end-product features such as periodic code updates or user-specific and application-specific reprogrammability. Such updates can occur at any point in the life of the drive and can include factory or field revisions to code around mechanical or media variations. "Integrating flash right on the DSP is a major breakthrough," said John Schanzenbach, TI's cDSP marketing manager. "Flash gives Seagate an easy reprogrammability path for periodic code upgrades and hardware reuse across their product line." TI's cDSP is the first such core technology available to integrate a DSP processing engine with flash memory for high-volume production. In addition to reducing cost, on-chip flash provides zero-wait-state access speeds that match the speed of the DSP core. Off-chip flash would have caused the Seagate design to incur performance-degrading wait states. TI's real-time emulation tools set, provided for cDSP development, allowed HDD interface code to be developed and debugged without stopping or hampering normal disk drive operation. The capability played a critical role in the development program at Seagate, making it possible to develop the uniprocessor architecture in time to meet a narrowly defined market opportunity window. | |
 Integration Home
|