Cirrus Logic Gets Serious About SOC

IC house Cirrus Logic (Fremont, CA) is engaged in a major effort to win the hearts and minds of systems builders designing at the systems-on-a-chip (SOC) level. Cirrus is rolling out high-speed, ultra-low-power RISC-based SOCs for pocket organizers and other information appliances, and is also pitching chips for the blossoming Internet audio player market.

Unveiled at the Microsoft Windows CE Developers Conference, Cirrus's highly integrated EP7211 chip is targeting OEM consumer designs that will retail between $150 and $300.

Among the few ICs currently on the market that supports both Microsoft Windows CE operating system (OS), and Symbian's (London, England) increasingly popular EPOC32, it includes an embedded Advanced RISC Machines' ARM720T microprocessor core. At 74 MHz, this RISC core is fast enough to equal the performance of a 100 MHz Pentium PC CISC.

As a 2.5 V chip, Cirrus's device also dissipates about 170 mW at full speed, which translates to extended battery life for portables. The SOC also provides built-in support for a high-contrast LCD, as well as a PCMCIA-compliant PC Card port and IrDA-compliant connectivity hooks.

Here Come Consumer Designs

Cirrus claims its new silicon is the first in a new generation of application-specific standard products, or ASSPs the firm is designing specifically for dedicated information appliances. According to market researchers at International Data Corp., it's a hot marketplace. IDC reports that the unit volume of low cost consumer-oriented information appliances will overtake PC volumes within the next few years--reaching a whopping 20 million units by the year 2002. "The demand is rapidly expanding," chimes Matthew Perry, vice president and general manager of Cirrus Logic's Embedded Processor Division.

"Unlike the big iron approach of maximizing system speed--along with dissipation and price--information appliances require an optimal approach," says Perry. "It must balance features with performance, power usage, and price." Perry says his latest embedded processor approach will hit the sweet spot of price and performance.

Leveraging Cirrus Logic's intellectual property (IP) portfolio, as well as experience with ARM cores, Perry says Cirrus will target specific vertical markets with these ASSPs. The goal is to offer OEMs off-the-shelf approaches that can ensure faster time-to-market than ASICS, as well as slash development costs associated with general-purpose microcontroller-based designs.

"As an IC vendor, ASSPs can let us respond quickly to manufacturers of PDAs, Internet audio players, GPS systems, e-books, and heldhelds for industrial applications," avows Perry. "In line with our strategy to offer developer-friendly chips that support multiple real-time operating systems (RTOSs), the EP7211 is among the first chips on the market that can run both WinCE and EPOC32, the two leading OSs for consumer handhelds."

Other Markets Too

Perry says the EP7211 will support additional RTOS platforms too, making it suitable for vertical markets that have specialized OS requirements. "Given that the market for RTOSs is fragmented, the flexibility to support multiple RTOSs and evolving requirements can provide a distinct advantage," he says.

Perry also emphasizes that the EP7211 delivers a high Mips/W ratio. Moreover, as Cirrus's third-generation ARM-core based chip, he claims the device will offer an unmatched ratio of price per Mips/W. "While alternative chips typically couple pricing and Mips--higher Mips parts command higher prices--we're the first IC company to offer high Mips at low prices."

Slashing Memory Footprints

To complement the device's ARM720T core, the EP7211 also provides an 8 kbyte, four-way set associative cache targeted at boosting memory subsystem throughput. What's more, because the EP7211 uses the ARM Thumb instruction set (it shrinks commonly used 32-bit instructions into 16-bitters), the EP7211 is claimed to exhibit as much as a 40% improvement in code density, helping to reduce system memory. The chip also incorporates 37.5 kbytes of on-chip arbitrated SRAM. It can be used as a frame buffer or as on-board memory to improve system performance and further reduce power.

Coupled with its memory management, the EP7211 also includes a dynamically selectable clock circuit. It can switch between 18 MHz, 36 MHz, 49 MHz, and 74 MHz clock rates on-the-fly. This software-controlled clock can conserve power by increasing processing speeds only when necessary.

Running at 18 MHz, an EP7211 typically dissipates 50 mW. In an Idle state, with the clock to the CPU stopped but all peripherals still running, the chip dissipates only about 15 mW. In Standby it coasts along at a very cool 50 microwatts. Neat, eh?

Built-in Peripherals

Although low power, the EP7211 also packs a suite of system peripherals that can slash the need for external power-hungry logic. Cirrus says that the IC also includes one the most flexible LCD controllers ever incorporated into a single chip solution; it's capable of handling displays up to 1024 pixels wide.

The device also includes a DRAM controller, two UARTs, the aforementioned IR interface, and a Y2K-compliant realtime clock. It also integrates multiple on-chip timers, 27 general purpose I/O pins, and an interface to the firm's type CL-PS6700 PCMCIA/Compact Flash Controller IC. The IC also packs in-circuit emulation (ICE) and silicon debug support via a JTAG port. Given this rich set of built-in peripherals, the EP7211 should only demand a few additional components to provide a rather complete and feature-laden handheld.

Pin-Compatibility

The EP7211 is also socket- and register-compatible with its predecessor, the Cirrus PS71111. If you've done a prior design with a PS71111, you should be able to rapidly port existing code from that project to the EP7211.

In terms of packaging, price and availability, the EP7211 comes in either a 208-pin LQFP or a 256-lead plastic ball grid array (PBGA) package. Samples, in limited quantities, are available immediately.

Cirrus says production quantities and a development board (which will be priced at just under $1,300) will be available in the third quarter. right now, the unit price for an EP7211 has been set at just a tad less that $15 a pop in LQFP flavors, at quantities of 100,000/year. It'll sell for under $18 in a PBGA.

Let's Hear It

Leveraging this ARM core-based SOC thrust into the audio domain, Cirrus is also readying another IC it calls the EP7209. This chip this IC targets OEM designers of personal digital audio players and Internet audio playback equipment--especially portables. Since the EP7209 uses the ARM72OTDMI logic core, it also takes advantage of the ARM Thumb instruction set.

The EP7209 is power managed. What's more, its chip structure uses power-saving techniques that can prolong battery life by as much as 50% compared to alternative multi-chip designs. Yet it offers impressive performance, with Mips to spare. The EP7209 operates at 74 MHz; like the EP7211, that's fast enough to equal the performance of a 100 MHz Pentium. Like the EP7211, it too dissipates only about 170 mW at 2.5 V.

As a multi-standard digital audio device, the IC is claimed by cirrus to be the first on the market to support both the popular MP3 standard, as well as other rapidly emerging Internet compression audio standards such as Microsoft Audio.

Cirrus also says its EP7209 provides the processing power to handle both Internet audio as well as value-added features, giving OEM designers lots of processing power freedom with which they can differentiate their designs.

Evolving In Lock-Step

Like the EP7211, the off-the-shelf EP7209 ASSP promises to help you cut manufacturing cost and shorten your time-to-market. Since Cirrus Logic also provides Crystal Semiconductor digital-to-analog converters (DACs), it's among the few vendors able to offer a total system for digital audio player developers. By the way, according to Cirrus Logic, the first MP3 players using its SOC should reach stores well before Christmas.

The current market for digital audio players, which enable consumers to download music directly from the Internet and store it in flash for playback, is estimated to blossom to as many as one million units this year. With Cirrus's new chip, OEMs should be able to quickly design new digital audio players at greatly reduced cost, and thus jump into this burgeoning and potentially lucrative marketplace.

For audio, the device's ARM core provides the processing throughput of a full-fledged digital DSP too. Indeed, the EP7211 packs a number of features directly related to sound quality, including digital bass, treble and volume controls, as well as low power playback modes, and capabilities for graphics equalizer, spectrum analyzer, and graphic level meter displays. The IC can also process audio output, enabling common musical effects such as reverb.

Using this chip, you can do Internet audio processing with only half the chip's available processing horsepower. This leaves up to 25 Mips for creative application to other functions that will distinguish your product in the marketplace.

Other features include support for a large memory array (4 kbytes) for an LCD, a parallel download interface, and an optional IrDA-compliant port for digital file transfers.

The EP7209 is sampling now, and is available in either 208-pin LQFP or 256-ball BGAs. The unit price is less than $12 at time of publication. A BGA version will set you back about $15.

Get more information on these two SOC products from Cirrus Logic, Inc., 310 West Warren Ave., Fremont, CA 94538. Phone: (510) 623-8300.