The Qualcomm Hexagon DSP architecture gone official now as it is being used by the new Snapdragon 820 processors. What is DSP? It’s is a specialized microprocessor or a SIP block and with its architecture optimized for the operational needs of digital signal processing and the Digital Signal Processor (DSP) goal will be usually to measure, filter and/or compress continuous real-world analog signals. More about DSP can be found here.
Qualcomm’s new Hexagon DSP was actually used on the Google Nexus 5 to double the battery life when playing MP3 files. Similarly the Hexagon 680 DSP brings in two new features, where it has both CPU and DSP functionality to support deeply embedded processing needs of the mobile platform for both multimedia and modem functions. The Hexagon architecture and family of cores provides Qualcomm Technologies a competitive advantage in performance and power efficiency for modern and multi-media applications and of course is the key component of all Qualcomm’s Snapdragon processors. DSPs are important for a number of unique applications such as voice processing, audio processing, and other input processing applications.
Today, Qualcomm elected to reveal a number of details about their Hexagon 680 DSP, which will ship in the Snapdragon 820. DSPs are a sort of in-between point in architecture design between highly efficient fixed function hardware (think: video decoders) and highly flexible CPUs and they are programmable, designed to do a limited number of tasks well, making them efficient at those tasks relative to a CPU, but more flexible than fixed function hardware.
In the case of the Hexagon 680, one of the key features Qualcomm is focusing on for this launch are Hexagon Vector Extensions (HVX). HVX is designed to handle significant compute workloads for image processing applications such as virtual reality, augmented reality, image processing, video processing, and computer vision.
Foremost is it has a dedicated DSP for sensor processing and is called low power island, which basically improve the battery life of functions that are always turned on such as step or actually sensors as well positioning sensors. Secondary is the HVX that is paired with Qualcomm Spectrum camera ISP to provide advanced imaging and computer vision. On device powered by Snapdragon 820 for instance, the ISP and DSP will work together to adaptively brighten images, videos that would have appeared to have been too dark on other phones. The Hexagon 680 in the Snapdragon 820 will also be able to have data from the camera sensor directly streamed to the L2 cache and shared with the ISP to avoid the power cost of going off-die to DRAM.
The Hexagon 680 will also be able to perform better, faster and at a much lower power consumtion of 10% compared to others. Now it looks like Qualcomm is digging all the necesssary elements that caused Snapdragon 810 overheating problems and with S820, which is a powerful chipset that can indeed cause battery life, so Qualcomm is using Hexagon 680 inside Snapdragon 820 Processors. It remains to be seen whether OEMs using Snapdragon 820 will use these DSPs to the fullest extent, but the Snapdragon 820 is shaping up to be a promising 2016 high-end SoC.