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News and New Products
Media, chip set address portable systems’ requirements
By Brian Dipert -- EDN, 1/6/2005
Samsung has shoehorned a 1.5-Gbyte Cornice Storage Element into its latest model SPH-V5400 cell phone, a trendsetting first step in a bigger picture flash-to-hard-disk-drive shift that EDN predicted after last year’s Storage Visions Conference at the Consumer Electronics Show (see “Harnessing the hard-drive metamorphosis,” EDN, July 8, 2004, pg 28). The concept has a lot of merit, as cell phones increasingly stretch beyond their communications roots and become media-rich, including audio, graphics, and still and video images; recording; and playback platforms. A quick—and sobering—show of hands, though: How many of you have ever dropped a cell phone? Traditional ruggedness-boosting approaches, such as shock absorption within the drive and of the drive subsystem; motion-sensor-instigated, aggressive “parking” of drive heads; and spin-down of platters, may be insufficient in this new class of small, portable, and casually handled devices.
Cornice’s latest single-head, $63 (1000), 3-Gbyte drive takes media protection to the next level with a sensor- or motor-controller-driven crash-guard active latch that, when the system properly implements it, enables the drive to survive a 1.5m fall (Picture). The Storage Element claims a 5-Mbyte/sec typical transfer rate, weighs 14.5g, and measures 42.8×36.4×5 mm. Power consumption of 3.3V reflects system buffering, consequently enabling aggressive spin-down power management; Cornice estimates 4.5-mW average power consumption at 3.3V during typical audio playback, 23 mW average during typical video playback, and 85 mW average during typical video recording. These power consumption approximations reflect system buffering, consequently enabling aggressive spin-down power management.
The new, fast-growing breed of 0.85-, 1-, and 1.8-in. hard-disk drives consists of more than a platter, a motor, an actuator, and a head. They also have a motor controller and preamplifier within the drive, plus hard-disk control, interface control, and read-channel encoding and decoding functions variably partitioned between the system and the drive. Agere’s $10 (100) TrueStore CE chip set for small-form-factor drives consists of the RC1100 read-channel device, which also integrates hard-disk-drive- and interface-control functions; the PA1100 preamplifier IC; and the MC1100 motor controller. “Agere has long been the signal-to-noise leader,” claims Strategic Marketing Manager Jeff Janukowicz; accurately placing and extracting the data signal is key to squeezing maximum storage capacity from minuscule disk platters.
Power consumption is another key consideration; Agere claims that a combination of a low-leakage process and a power-cognizant chip design enables the RC1100 to consume 70% less power in deep-sleep mode than functionally equivalent devices targeting 2.5-in. drives. The PA1100, similarly, consumes as little as one-third the power of chips supporting 2.5-in. drives. Addressing reliability, the MC1100’s emergency-retraction feature parks the drive heads within a drive-dependent few milliseconds upon sensing physical shock or power loss. And regarding performance, the company claims that the chip set can deliver read and write speeds that top 350 Mbps to and from the rotating magnetic media and associated buffer memory. The on-die memory is 3 Mbits, split between buffer- and code-shadowing functions and sufficient to mask hard-disk-drive head-seek latencies; you can implement additional buffer memory in-system or by using a multidie package. The RC1100 is now available in sample quantities; the PA1100 will appear by the end of this quarter with the MC1100 following next quarter.
Agere Systems, 1-610-712-4323, www.agere.com.
Cornice, 1- 303-651-7291, www.corniceco.com.
