Mobile Processor Basics: Sub-processors
July 24, 2012
In our previous post on mobile processor basics, we introduced readers to the basic functions of mobile application processors (APs) and their major components, the CPU and GPU. In this post, we’ll revisit the GPU to further explain the role of sub-processors.
What is a Sub-processor?
Mobile APs are similar to computer processors, but due to size constraints, their components have to be condensed onto a single chipset, known as a System-on-a-Chip (SoC). Sub-processors allow for two very important things: division of labor and specialization of function. For performance to be optimized, the CPU cannot handle all of a mobile device’s functions; so sub-processors take on a supporting role, carrying out specialized tasks so that the CPU is free to handle core functions.
The number and types of sub-processors depend on the individual SoC. Examples of common sub-processors include video encoders and decoders, camera operation and audio playback. Some mobile APs, such as those produced by Exynos, separate the modem (Wi-Fi, Bluetooth, GPS and 3G/4G) from the SoC, while others delegate these functions to their own sub-processor.
Sub-processors in Action
To demonstrate one of the roles that sub-processors take on within a chipset, we’ll take a closer look at the Exynos 5 Dual . In addition to dual CPU cores, the Exynos 5 Dual has a GPU, a sub-processor that handles specific, related functions.
The graphics processing unit (GPU) handles graphical and visual data within the system. Existing separately from and in support of the CPU, this GPU is responsible for generating the world’s best mobile 3D and 2D multimedia performance. A 1080p 60fps Multi-format Video Hardware Codec allows your mobile device to decode and encode many different file types. The chipset’s 8MP 30fps Image Signal Processor (ISP) is also located here, contributing to high-quality camera performance in equipped devices. The JPEG Hardware Codec rounds out this sub-processor’s extensive functionalities.
Depending on the manufacturer, other sub-processors often contribute to high-level performance in mobile APs, but learning about the GPU should give you a good understanding of how a sub-processor functions and the type of roles it can fulfill. To learn more about mobile APs and how they affect smartphone and tablet performance, visit us on the Samsung Exynos website.