Startup Aims For Best Of Both Worlds With Its PRML Chip Families
Cupertino, California (May 6, 1996) –
Marvell Semiconductor, Inc., a one-year-old startup company, today introduced two families of Partial Response Maximum Likelihood (PRML) read-channel chips that offer the speeds of analog PRML ICs with the functional richness of digital PRML designs. In addition, these products feature small die size, full-scan-test design, and low power consumption. Marvell's MVL88P and MVL88E chip families enable drive manufacturers to implement the most advanced, full-featured, channel technology at the lowest cost. What's more, by virtue of the unified architecture, low cost, and broad performance range (50 to 200 Mb/sec), Marvell is the first company to offer disk-drive manufacturers a complete PRML read-channel solution.
Marvell's team has considerable expertise in mixed-signal IC design, production, marketing, and sales, and are targeting their high-performance mixed-signal and digital products at high-speed computer, storage, communications and multimedia systems markets.
Products for the storage market came first because the opportunity was the most imminent. "Until now, there has been no single PRML chip that had the speeds and low-power consumption of analog combined with the functional richness of digital. Marvell's chip families have achieved that distinction," said Dado Banatao, Marvell's chairman.
Whereas others have produced PRML ICs using BiCMOS technology, Marvell is producing its chips in mainstream 0.5 micron digital CMOS technology. "By using a pure CMOS approach, our chips can be built reliably — and in volume — by any of a large number of worldwide IC manufacturers," explained Sehat Sutardja, Marvell's founder, president, and chief executive officer.
Marvell is ensuring the availability of its products by engaging in manufacturing partnerships with world-class IC manufacturers, such as Taiwan Semiconductor Manufacturing Company. "By using this mainstream process technology, we've also driven chip costs down very aggressively, and ensured our ability to continue to do so," Sutardja added.
Huge Market Potential
If the disk-drive industry can continue to increase capacities (currently by 60 percent per year), and continually lower its per-megabyte prices (currently by 12 percent per quarter), IDC, a market analysis firm, predicts the industry will be shipping over 160 million drives in 1998. However, to meet those capacity and price expectations, the industry has to adopt a new read-channel technology. Simply put, the contemporary peak-detection technology cannot continue to do the job.
PRML technology is the prime candidate for peak-detection replacement. PRML can sustain increased densities and speeds well beyond the limits of peak detection. The challenge is to produce such components at a price that sustains the per-megabyte price reductions. Current prices are about $10 to $15 whereas the industry is pressing for chips that cost about half that much. For those competitors who can profitably produce PRML ICs that sell for under $10, the 1998 disk-drive market is holding out a $1 billion reward.
"The key to low-cost IC design and production is small die size and high yields," said Pantas Sutardja, vice president of engineering at Marvell. "BiCMOS designs typically produce larger die sizes and lower yields than a pure CMOS technology. Thus, Marvell is in a better position to meet price expectations than its BiCMOS chip competitors," he reasoned.
PRML — Ready For Prime Time
For over 20 years, hard-disk drives have been designed with peak-detection read channels. Essentially, peak-detection indicates the occurrences of "peak" magnetic energy instances as the read head passes near the surface of the rotating disk. These peaks represent bits that have been previously "written" to the surface by a write head responding to electronic pulses. However, as drive makers keep pushing for higher bit densities, spatial separation between peaks grows smaller, and peak-detection error probabilities increase.
PRML read-channel technology uses sophisticated predictive algorithms to identify the most likely bit sequence in a captured read-signal sequence. Close spacing of peaks is much less of a degrading factor in PRML detection and accuracy, giving it significant advantages over peak detection.
The challenge has been to integrate all the core functions of PRML into a single-chip solution, and do it at a cost commensurate with the disk-drive market's expectations.
Inherently a mixed-signal (i.e. analog and digital) implementation, PRML ICs differ in the proportion of functions designed in analog and in digital. These differences, in turn, translate into differences in speed, functionality, power consumption, die size, and cost.
Just last year, most hard-disk drives were still being built with older, peak-detection read-channel ICs, but designs for new drives are rapidly shifting to PRML. By 1998, virtually all new drives will be incorporating this technology, and the ramp up will begin in late 1996 and 1997.
Marvell's Products In Perspective
Today's PRML ICs fall chiefly into two categories — primarily analog or primarily digital. Analog PRML ICs were first to market, and offered high speeds, modest power consumption, but only bare-bones PRML functionality. Digital PRML ICs followed, offering more functionality but coupled with a tradeoff in speed, cost, die size and power consumption.
The ideal solution is to marry the speed and low-power characteristics of the analog IC with the functional richness of the digital implementation. This is precisely what Marvell has accomplished, in less than nine months, and in its first tape out. In addition, Marvell's products have small die size and full-scan testability. The latter enables manufacturers to procure zero-defect components without having to pay exorbitant premiums. Design innovations have also kept power consumption at parity with the next generation of analog solutions, and at just half that of the currently available digital solutions. Furthermore, automatic power-management modes achieve a further 30 percent reduction in power consumption during typical operation cycles.
Marvell's first products are high performance, fully-integrated, read-channel ICs. The MVL88P family implements a partial-response class IV (PR4) read channel; the MVL88E family implements an extended PR4 (EPR4) read channel to provide up to 20 percent greater areal density.
The fully programmable, 8-tap Finite Impulse Response (FIR) equalizer on both chips permits drive makers to squeeze out user bit densities of 2.8 (compared with the current norm of 2.0), thereby helping to increase user data capacities while reducing costs. What's more, Marvell's proprietary 8/9 encoding/decoding (ENDEC) provides high data reliability and low error rates without having to use a data randomizer to achieve it.
By designing the products as "digital" PRML ICs, Marvell is able to support a rich set of ancillary functions. For example, these Marvell ICs can be used to build self-calibrating hard-disk drives. That is, the MVL88P and MVL88E families can detect and compensate for magnetic variations that occur on every disk. This can eliminate a lot of time and cost (labor and equipment) now required to match disk, heads and electronics (called "channel integration"). In addition, the Marvell products are designed to tolerate a wide range of media and head variations, allowing disk-drive manufacturers to build very reliable products using lower-cost parts. Furthermore, disk-drive manufacturers can use these ICs' channel- statistics-gathering capabilities to provide their customers with early-warning indications of near-term drive failures. The early warning can alert users to backup disk contents well before the possibility of data loss.
Packaged in 80-pin TQFPs, the Marvell PRML read-channel ICs are 5-volt only components that typically consume less than 0.8 watts at up to 200 Mbits per second, and even less than 0.5 watts when employing built-in power management modes.
The First Complete PRML Solution
The combination of low cost, and a range of 50 to 200 Mbits per second, makes Marvell's products attractive for a wide range of drive designs, from the highest performance types to price-sensitive commodity drives. Moreover, by adopting a unified architecture, Marvell is providing its customers with software interface compatibility across the entire range of products, as well as for future generations. Thus, disk-drive vendors using Marvell's PRML ICs can minimize their redesign efforts, reduce their integration time, reduce their risk, and get new drives to market more quickly.
Price and Availability
Samples of Marvell's MVL88P are available now, and production quantities of these products are scheduled for the third quarter of 1996. MVL88E product sampling is expected later in the third quarter of 1996. Quantity pricing is still being reviewed, but Marvell expects to sell these products in quantity for under $10.
Marvell Semiconductor, Inc. is a privately-held company that is an expert in the design, development and production of high performance, high value-added, mixed-signal integrated circuits. Its products are designed for computer, data storage, and multimedia systems markets.