Adaptec shows integrated DSP/disk drive devices

Electronic News, Sept 19, 1994

MILPITAS, CALIF. - Adaptec has taken the wraps off the first of a planned family of programmable disk drive manager chips that use the Pine 20MIPS digital signal processor from DSP Group as its core and integrates the functionality of up to four ICs into one device.

The AIC-4411 is touted by Adaptec as an integrated drive manager chip (DMC) that combines the functionality of a microcontroller with other drive management tasks. The AIC-4411, along with an external disk drive controller, is designed specifically for high-volume disk drives. Built around the Pine DSP core are a set of digital and analog blocks for managing the functions of a hard disk, including servo/spin, data path control and the interface for read channel control.

"The AIC-4411 is architected to optimize performance in master mode. The integration of the 20MIPS DSP core, combined with programmable functions specifically adapted for hard disk drives, completely eliminates the local microcontroller and improves performance," asserted Mike Fisher, GM of Adaptec's Mass Storage Electronics business. "The AIC-4411 supports several microcontroller and servo logic functions as well as analog-to-digital conversion (ADC) and digital-to-analog conversion (DAC) functions simultaneously, for greater overall disk drive performance at the lowest cost."

In the future, the company plans to combine its AIC-4411 with one of its head disk controller (HDC) devices to provide a single-chip integrated disk servo controller solution.

The new AIC-4411 can be configured for either master mode or slave mode. In master mode, the DMC is said to replace the traditional host controller MPU by managing the data path and interface functions as well as up to two analog IC, and the servo/spin function. In slave mode, the device executes the servo/spin function under the supervision of a local MCU.

In master mode, the DMC automates the functions of the peripherals to off-load the DSP, then optimizes the interface to the sub-blocks. This reduces the servo/spindle process time and creates additional bandwidth to process remaining functions of the hard drive system, according to Adaptec. To enable data path and interface functionality, a memory control and peripherals were added. Additional programmable control signals were incorporated to interface to a variety of commercially available read channel, power driver and interface ICs.

To validate the DMC's performance for data path control, Adaptec bench-marked its error correction and checking firmware, using error correction code (ECC) developed by an external consultant, against a Texas Instruments C25 DSP and Intel's 8C196 MPU. The results were a claimed 75 percent reduction in execution time with the DMC, while maintaining a comparable code size.

Additional features include single cycle multiply accumulate for servo processing, and on-chip ADC of 1.1 microseconds that is said to reduce overall servo processing time by a factor of six compared to a composite of competitors, maximum ADC specs.

Adaptec said it can customize the DMC to fit the drive developers, architecture for high-volume applications. In addition, the AIC-4411 comes with a set of hardware and software tools. The DSP programming tools include C compiler, simulator, assembler and linker. Built-in diagnostic functions are provided to simplify the drive development process. Adaptec also provides its customers operational servo and host interface software packages to reduce development time.

The company said it has demonstrated the capability of the AIC-4411 on a number of new customer head disk assembly (HDA) platforms, and the HDAs were made to perform spin, track and seek functions in four weeks. Although Adaptec would not disclose the beta customers for the new product, existing disk drive customers include most of the drive manufacturers, such as Seagate, Conner Peripherals and Maxtor.

The AIC-4411 is sampling now in a 128-pin TQFP for $15, with volume production slated for 1Q95.