System on a chip
An integrated circuit combining key computer components on one chip.
A system on a chip (SoC) is a single integrated circuit that packs together most or all of the essential parts of a computer or electronic system. This typically includes a central processing unit (CPU), memory, input/output controls, and data storage management, with extras like a graphics processing unit (GPU), Wi-Fi, or radio frequency processing often added. By combining so many functions, an SoC cuts down on the need for separate components, which improves power efficiency and makes device design simpler.
High-performance SoCs usually work with dedicated memory chips, such as LPDDR, and flash storage like eUFS or eMMC. These can be stacked directly on top of the SoC in a package-on-package (PoP) setup or placed nearby on the motherboard. Some SoCs also team up with specialized chips, like cellular modems.
At their core, SoCs integrate one or more processor cores with critical peripherals. This approach is similar in concept to a microcontroller but offers much more computing power. The unified design uses less power and takes up less semiconductor die area than traditional multi-chip setups, though it sacrifices modularity and the ability to replace individual components.
SoCs are everywhere in mobile computing, where compact, energy-efficient designs are essential. They power smartphones, tablets, and smartwatches, and are becoming more common in edge computing, where data is processed in real time near its source.
**Types**
Broadly, there are three kinds of SoCs:
- SoCs built around a microcontroller, - SoCs built around a microprocessor, often found in mobile phones, - Specialized application-specific integrated circuit (ASIC) SoCs designed for particular tasks that don't fit the first two categories.
**Applications**
SoCs can handle any computing job, but they are most often used in mobile devices like tablets, smartphones, smartwatches, and netbooks, as well as in embedded systems and applications where microcontrollers were once the norm.
**Embedded systems**
SoCs are becoming more prominent in the embedded systems market, where microcontrollers used to dominate. Tighter integration offers better reliability and mean time between failures, while SoCs provide more advanced features and computing power than microcontrollers.
- Types
- Three distinguishable types: SoCs built around a microcontroller, SoCs built around a microprocessor (often found in mobile phones), and specialized application-specific integrated circuit SoCs.
- Common processor architecture
- Arm architecture is a common choice for SoC processor cores.
- Typical memory technologies
- ROM, RAM, EEPROM, and flash memory; RAM subdivided into SRAM and DRAM.
- Example embedded socs
- STMicroelectronics STM32, Raspberry Pi Ltd RP2040, AMD Zynq 7000.
- Example mobile socs
- Samsung Exynos, Qualcomm Snapdragon, MediaTek Dimensity & Kompanio Series.
- Early personal computer soc
- Acorn Computers produced the ARM250 SoC in 1992, combining ARM2 processor with memory, video, and I/O controllers.
Lore & Background
Fundamentally, SoCs integrate one or more processor cores with critical peripherals, conceptually similar to a microcontroller but with far greater computational power. This unified design delivers lower power consumption and a reduced semiconductor die area compared to traditional multi-chip architectures, though at the cost of reduced modularity and component replaceability. High-performance SoCs are often paired with dedicated memory (such as LPDDR) and flash storage chips (such as eUFS or eMMC), which may be stacked directly on top of the SoC in a package-on-package configuration or placed nearby on the motherboard. Some SoCs also operate alongside specialized chips, such as cellular modems.
In 1992, Acorn Computers produced the A3010, A3020 and A4000 range of personal computers with the ARM250 SoC, which combined the original Acorn ARM2 processor with a memory controller, video controller, and I/O controller—previously four discrete chips. The ARM7500 chip was their second-generation SoC, based on the ARM700, VIDC20 and IOMD controllers, and was widely licensed in embedded devices such as set-top-boxes. SoCs are ubiquitous in mobile computing, powering smartphones, tablets, and smartwatches, and are increasingly important in edge computing, where real-time data processing occurs close to the data source.
Reader's Guide
SoCs are applied to any computing task but are typically used in mobile computing such as tablets, smartphones, smartwatches, and netbooks, as well as embedded systems and applications where previously microcontrollers would be used. In the embedded systems market, tighter system integration offers better reliability and mean time between failures, and SoCs provide more advanced functionality and computing power than microcontrollers. Applications include AI acceleration, embedded machine vision, data collection, telemetry, vector processing, and ambient intelligence. Embedded SoCs often target the internet of things, multimedia, networking, telecommunications, and edge computing markets.
Mobile computing SoCs always bundle processors, memories, on-chip caches, wireless networking capabilities, and often digital camera hardware and firmware. High-end SoCs may have no memory and flash storage on-chip, instead placing them nearby or above in a package-on-package configuration. Examples include Samsung Exynos, Qualcomm Snapdragon (used in many smartphones and, by 2018, as the backbone of Windows 10 laptops marketed as 'Always Connected PCs'), and MediaTek Dimensity and Kompanio Series. On modern laptops and mini PCs, low-power variants of AMD Ryzen and Intel Core processors use SoC design integrating CPU, IGPU, chipset, and other processors in a single package, though they still require external memory and storage chips.
Did You Know?
- An SoC must have at least one processor core, but typically has more than one core.
- The ARM250 SoC, used in Acorn personal computers in 1992, combined four previously discrete chips into one.
- SoCs can include analog interfaces such as analog-to-digital and digital-to-analog converters for signal processing.
- Digital signal processor (DSP) cores on SoCs often feature very long instruction word (VLIW) and single instruction, multiple data (SIMD) instruction set architectures.
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