The Dhanush Wearable Processing Unit is a Linux-ready SoC based on MIPS MicroAptiv and InterAptiv cores, designed for wearables with 30-day battery life.

Based in Santa Clara, Calif. and Hyderabad, India, Ineda Systems announced its Dhanush Wearable Processing Unit (WPU) back in April. The system-on-chips have now begun sampling to early customers. A June 4 blog entry from Imagination Technologies promoted the technology, as well as Imagination’s underlying MIPS MicroAptiv and InterAptiv processors, which drive the wearables-oriented chipset.

With the help of $17 million in funding from companies including Qualcomm and Samsung, the 180-person start-up hopes to ship its Dhanush WPU chipsets and reference designs in volume by the second half of the year. The company’s chairman is Sanjay Jha, previously CEO of Motorola Mobility and COO at Qualcomm.

Simplified (left) and detailed (right) architectural diagrams for the Dhanush WPU. Note that the purple items at right depend on the model. Only the Advanced model appears to have an InterActiv CPU, as well as the PowerVR GPU and coprocessors.
(click images to enlarge)

The Dhanush WPU is available in four tiers, all of which provide 30-day battery life, and up to 10x power consumption reduction compared to the current generation of application processors, claims Ineda. All four models offer a sensor hub CPU subsystem that provides for always-on sensor functionality, and support a range of connectivity, starting from Bluetooth LE for the lower-end models, on up through Bluetooth and WiFi for higher-end models.

All the SoCs are built on a scalable computing architecture called HCA (Hierarchical Computing Architecture). Ineda claims its HCA technology enables applications and tasks to run “at the optimal level of performance and power and within the right memory footprint.”

Ineda’s Hierarchical Computing Architecture

With Ineda’s HCA, all the CPUs in a system can be individually or simultaneously active, working in sync while handling specific tasks assigned to them independently. This hardware and software framework offers a tiered multi-CPU architecture that can share peripherals and local memory “so multiple CPUs can run independently and create a unified application experience for the user,” says the company. HCA is also touted for its “superior power optimization capabilities.”

It’s unclear whether the Dhanush WPUs are based on the older MicroAptiv and InterAptiv designs or the new Warrior cores. The latter are binary-compatible with existing MicroAptiv and InterAptiv models, and are tiered accordingly. They include a high-end MIPS Series5 Warrior-P model based on the ProAptiv core, aimed at smartphones and tablets.

Four tiers of Dhanush WPU
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The four Dhanush WPU models include:

• Nano — Designed for simple health trackers and smartbands, the Nano runs an RTOS (real-time operating system) on its single MicroAptiv MIPS core.

• Micro — The Micro design implements a higher-end, dual-core MicroAptiv model that integrates an MMU and local caches, and can run a stripped-down Linux distribution or a high-end RTOS.

• Optima — The Optima, which also integrates two MIPS cores, targets “mainstream smartwatches,” and appears to run mainstream Linux distros. It offers an external memory option via a low-power LPDDR2 interface.

• Advanced — The WPU implements three MIPS cores plus a pair of Imagination PowerVR graphics engines, and can run Linux or Android. With support for multitasking, high resolution rendering, image/video processing, and low power video recording and playback, it’s a good match for smart glasses and other advanced wearables, says Ineda.

Shastra-A (left) and Shastra-M reference boards
(click images to enlarge)

The Dhanush WPUs are supported with a Shastra-A reference board for the Advanced and Optima SoCs, and a Shastra-M board for the Micro and Nano. Each features a Software Development Kit (SDK) with:

• Unified development environment (OS, Drivers, Services, APIs, Sample Applications)
• Integrated resource management
• Integrated power management
• GUI framework
• User guides, tools, and build utilities
• Power profiling tools

“Strict power constraints are the greatest technological challenge for smart wearables, and Ineda is the first company taking this challenge truly seriously at the SoC level with Dhanush,” stated Chris Jones, VP and principal analyst at Canalys. “Always-on sensor functionality is also critical and inherent to its design.”
 
Further information

The Dhanush WPU SoCs are sampling now to early customers, along with SDKs. Volume production is expected in the second half of the year. More information may be found at the Ineda Systems Dhanush WPU product page, as well as the Imagination Technologies blog announcement.