Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Processors/DSPs

?Watt controller advances HDD adoption in embedded systems

Posted: 10 May 2005 ?? ?Print Version ?Bookmark and Share

Keywords:intel? pxa2xx? processor?

Intel Corp.'s PXA2XX processors continue to gain huge support in high-growth mobile consumer applications, creating a need for high-performance low-power bridging solutions to enable the adoption of emerging networking, storage and media technologies in handheld and portable equipment.

Typically, traditional FPGA and CPLD products would fill that need; however, PLD makers have shied away from serving the market.

Not QuickLogic Corp. The company has developed a product strategy that helps designers expand the Intel PXA2XX processor's native interface set to communicate with different devices.

By outfitting one of its ?Watt programmable controllers from its Eclipse II series for the Intel PXA2XX processor line based on Intel's Xscale architecture, the PXA2XX processor's native interface set can now communicate with IDE-based hard disk drives.

QuickLogic provides many different interfaces needed for the embedded processors. One good example is WiFi. Most of the 802.11a/g chipsets out there today are based on miniPCI, CardBus, or USB 2.0. However, none of the embedded processors out there supports those interfaces. Through Intel PXA's VLIO, QuickLogic last month made a miniPCI bridge to connect to the WiFi module to demonstrate this capability.

QuickLogic's moves underscore its commitment to accelerate the adoption of emerging technologies not natively supported by Intel's PXA2XX processors.

Low-power, high performance

Several steps were taken to ensure that its Eclipse II QL8050 5Watt programmable hard disk drive controller provides the highest system bandwidth at the lowest power consumption, according to Itsu Wang, product marketing manager at QuickLogic.

First, the standby power consumption of the controller is based on microAmp, which is negligible for the system power budget of portable media players, Wang explained.

The company also implemented power management circuitry in its controller that allows the host processor to power down the hard disk drive to a standby state via a programmable IO, or to a powered-down mode via a programmable IO driving a FET. The disk drives typically draw a few hundred milliamps in active mode; the more time they can be put into standby mode, the better.

Lastly, the controller's sector RAM can buffer a full 512-byte sector from the hard disk in both the read and write directions, enabling 10Mbps throughput.

"The high throughput allows systems to transfer data to and from the hard disk drive in a short amount of time. Less time means the drive or the host processor can be put in a standby mode sooner, thereby consuming less system power," he said.

By embedding dedicated sector buffers and offloading the PXA processor from managing the overhead of IDE timing and polling operations, the controller enables the PXA processors to operate on other processor-intensive tasks.

"This is very important because the processor is handling multi-tasks. If the processor needs to emulate the IDE interface with its own DMA engine, it will occupy about 40 percent of its utilization. Because we handle all the IDE timing and register, we can offload that 40 percent of CPU utilization. CPU will treat our bridge as a standard memory, because it is connected through VLIO (Variable Latency IO), which is static memory interface," Wang said.

As a result, the processor is free up to do other tasks. And it is interrupt driven instead of using a polling mechanism, which again will offload the processor's intensity, he added

The ?Watt programmable hard disk drive controller costs $5 in volume quantities.

HDD solution pack

QuickLogic is also offering a HDD solution that includes a daughtercard for the Intel PXA270-based processor developer's kit and a board support package (BSP) for the Windows CE and Mobile operating systems. The company also plans to release a BSP for Linux.

The daughtercard supports all IDE-compatible HDDs, including the 1.8-inch and 1-inch form factor miniature disk drives.

The product enables designers to make system architecture tradeoffs on power consumption, performance and cost to improve time-to-market and reduce risk.

The ?Watt programmable controller and HDD solution pack are suitable for designers looking to add hard disk storage to Intel PXA2XX-based portable embedded systems, such as handheld navigational equipment, portable media players and portable medical systems.

The HDD solution pack is sampling and expected to be in production by the end of May.

- Ismini Scouras


Article Comments - ?Watt controller advances HDD ...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top