A Much Better Audio Solution

The Xtensa HiFi 2 Audio Engine is an add-on to Tensilica's benchmark-breaking Xtensa LX processor. Tensilica's engineers used the following capabilities to create a specially optimized configuration of the Xtensa LX processor for this engine:

• Custom instructions (better code density, fewer cycles)
• Includes Variable Length Decode (VLD)
• Flexible data-path widths (higher efficiency per cycle for high fidelity audio)
• Multiple instructions per cycle (VLIW - higher efficiency per cycle for higher fidelity)
• Simultaneous data operations (SIMD - parameterization)

Tensilica's Xtensa HiFi 2 Audio Engine maintains full 24-bit resolution throughout. This resolution provides audibly superior quality over 16-bit competitors, making it ideal for high-quality consumer applications.

Because the processor is not hardened, designers can make further modifications to have the processor exactly match the intended application. Any further changes to the Xtensa HiFi 2 Audio Engine will be reflected in the entire software tool chain automatically created by the Xtensa LX processor generator for ease of integration.

Simplified Programming

A key advantage of the HiFi 2 Audio Engine is its simple programming model. Because of the efficiency of the optimized audio and voice instructions, software developers can port audio and voice codecs completely in C while maintaining or surpassing the performance of assembly on other DSP and CPU architectures.

See the SONiVOX Success Story to see how SONiVOX ported their software to the HiFi2 Audio Engine.

Power Savings

Through a combination of significantly lower power per MHz and architectural optimization of the HiFi 2 Audio Engine instruction set, the HiFi 2 Audio Engine delivers dramatic improvements in energy efficiency that lead to increased battery life for portable and wireless applications. Based on TSMC’s 65 nm LP process and a minimal HiFi 2 configuration,
power including memories is as low as 66 µW/MHz dynamic and 69 µW static. Decoding a typical MP3 file at 5.7 MHz requires only 0.46 mW of total power. For the Diamond 330HiFi core, power ranges from 0.089 – 0.352 mW/MHz in 0.13G and is typically 0.148 mW/MHz in TSMC 90 nm G.

Lower Gate Count

Through careful engineering and by fully exploiting the features of the Xtensa LX architecture, Tensilica was able to implement the Xtensa HiFi 2 Audio Engine in approximately 45K gates. A minimal configuration, including the Xtensa LX processor, is approximately 67K gates. For the Diamond 330HiFi core, the die area, post synthesis, flop based is approximately 0.60 mm² post-route in 90G.

Performance to Spare

Because of the efficiency of the Xtensa HiFi 2 Audio Engine architecture, it requires only a fraction of the available MHz to perform the audio decoding and encoding functions. Targeting high-performance applications, it can support speeds greater than 300 MHz in TSMC 90G and 450 mHz in TSMC 65GP, leaving lots of headroom for other control, media, and signal processing tasks.

For an in-depth look at the instructions added to the Xtensa LX processor for the Xtensa HiFi 2 Audio Engine, please read the product brief.