Caence/Tensilica shapes DSP IP for low-energy SoC implementations

April 23, 2015 // By Graham Prophet
Tensilica’s Fusion DSP is configured for applications in connected devices, wearables and other scenarios when significant processing or pre-processing of data is required close to the point of data capture, and where power resources are limited; the company describes it as flexible and scalable DSP for applications requiring ultra-low power in a small footprint.

The current trend to a large upswing in sensors, sensor data collection and the associated need for data processing calls for a suitable DSP-capable resource, Cadence says; the Fusion digital signal processor (DSP) is based on the Xtensa Customizable Processor, and Cadence is aiming it at applications requiring merged controller plus DSP computation, ultra-low energy and a small footprint. It can be designed into systems on chip (SoCs) for wearable activity monitoring, indoor navigation, context-aware sensor fusion, secure local wireless connectivity, face trigger, voice trigger and voice recognition.

The IP comes with “pre-built” options for common requirements spanning communications standards; optional Instruction Set Architecture (ISA) extensions are included to accelerate multiple wireless protocols including Bluetooth Low Energy, Thread and Zigbee using IEEE 802.15.4, SmartGrid 802.15.4g, Wi-Fi 802.11n and 802.11ah, 2G and LTE Category 0 release 12 and 13, and global navigation satellite systems (GNSS).

As with other Xtensa IP, Tensilica provides an “IDE generator” ; if you add extensions to the basic IP, the software will genrate both the processor IP, and and optimised set of development tools to match.

As a reference for a typical low-power application, Cadence quotes a power diagnostic derived from the Sensory Truly Handsfree always-on algorithm; running that, it says, the Tensilica Fusion DSP sets a new ultra-low-power benchmark using 25% less energy compared to the current low-power Cadence Tensilica HiFi Mini DSP. The company says that, as an optimised DSP architecture, it retains a significant performance margin in DSP tasks over a microcontroller with DSP capabilities. The IP comes with RTOS support, from its introduction date; OS ports are to the core Xtensa architecture – which is essentially unchanged in this introduction – so OS ports are relatively simple.

The Tensilica Fusion DSP combines an enhanced 32-bit Xtensa control processor with base DSP features and flexible algorithm-specific acceleration for a fully programmable approach, supporting multiple existing and developing standards and customer algorithms. Many IoT