System on a chip

System on a chip
Name	System on a chip
Caption	A generalized block diagram of a typical SoC.
Invented	Late 1990s
First producer	LSI Logic, Texas Instruments, Altera
Common manufacturers	TSMC, Samsung Electronics, GlobalFoundries, Intel

System on a chip. A system on a chip is an integrated circuit that integrates all or most components of a computer or other electronic system onto a single microchip. It typically combines a central processing unit, memory, input/output ports, and secondary storage, often alongside specialized accelerators for graphics or signal processing. This high level of integration is fundamental to the functionality of modern mobile and embedded devices, enabling compact form factors, high performance, and improved power efficiency. The design and production of these chips represent a pinnacle of semiconductor device fabrication and electronic design automation.

Overview

The concept consolidates key electronic subsystems, which historically required multiple discrete chips, into one silicon die. Early implementations emerged from companies like LSI Logic and were propelled by the demands of the personal digital assistant and early smartphone markets. The architecture is defined by its use of a standardized on-chip interconnection network, such as an Advanced Microcontroller Bus Architecture or Network on a chip, to facilitate communication between intellectual property cores. This integration is distinct from a traditional central processing unit or microcontroller, as it incorporates more heterogeneous, application-specific components. The rise of the SoC is inextricably linked to the success of products like the iPhone and the proliferation of the Internet of Things.

Design and architecture

A typical SoC design incorporates several pre-designed functional blocks, known as intellectual property cores, acquired from vendors like Arm Holdings or developed in-house. The computational heart is often an application processor utilizing an ARM architecture or RISC-V instruction set, accompanied by a graphics processing unit from companies such as Imagination Technologies or Qualcomm. Essential components include a memory controller for interfacing with dynamic random-access memory, various input/output controllers for Universal Serial Bus and PCI Express, and dedicated units for digital signal processing. Advanced designs may also integrate a neural processing unit for machine learning tasks, modems for cellular connectivity, and security subsystems featuring a trusted execution environment.

Applications

The primary application domain is mobile computing, with SoCs from Apple (Apple silicon), Qualcomm (Snapdragon), and MediaTek powering the vast majority of smartphones and tablet computers. They are equally critical in embedded systems, found in digital television sets, video game consoles like the Nintendo Switch, and network-attached storage devices. The automotive industry employs them in advanced driver-assistance systems and infotainment units, while the Internet of Things ecosystem relies on low-power SoCs for sensors and smart home gadgets. High-performance computing is also adopting the paradigm, as seen in AMD's Accelerated Processing Unit and custom chips for Google and Amazon Web Services.

Development and programming

Creating an SoC is a complex process leveraging sophisticated electronic design automation tools from companies like Cadence Design Systems and Synopsys. The design flow involves hardware description languages such as Verilog and VHDL for register-transfer level design, followed by logic synthesis and physical design stages. Software development typically occurs on a pre-silicon simulation model or a field-programmable gate array-based prototype. Programmers interact with the hardware through a software stack that includes a board support package, an operating system like Linux or Android, and tailored drivers. Key programming challenges involve managing power states, leveraging heterogeneous cores, and ensuring real-time performance for critical tasks.

Comparison with other integration methods

An SoC differs from a system in package, which combines multiple discrete silicon dies in a single package, a technique used by Intel for certain processors. It offers greater integration and potential performance per watt than a traditional motherboard-based design using a chipset with a separate central processing unit, northbridge, and southbridge. Compared to a microcontroller, an SoC is generally more complex, includes higher-performance application processors, and targets more computationally intensive applications. The line between advanced microprocessors and SoCs has blurred, with companies like Intel and AMD integrating features like graphics processing units and memory controllers directly onto the CPU die in a manner analogous to SoC design.

Market and industry trends

The global SoC market is driven by continuous demand for mobile devices, expansion of the Internet of Things, and the growth of artificial intelligence at the edge. Leading foundries like TSMC and Samsung Electronics compete on advanced process nodes, such as 5 nm process and 3 nm process, to manufacture these chips. There is a strong trend towards domain-specific architectures, with companies like Google designing tensor processing units and Nvidia integrating deep learning accelerators. The industry is also witnessing increased vertical integration, with large OEMs like Apple and Google designing custom SoCs to optimize their product ecosystems, challenging traditional merchant chip suppliers like Qualcomm and MediaTek.

Category:Integrated circuits Category:Computer hardware Category:Digital electronics