The Power of SoC in the IoT World
In this electronic world, the dominance of Integrated Circuitsis quite predominant and there comes a need for having a compact design system in place thatcan use less power, and less space but can deliver robust performance. A System on a Chip is one such Integrated Circuit that consolidates the need for having multiple components. A System on a Chip combines all system components into one piece of silicon.
In this article, you will understand in detail about the basics of System on a Chip usually called SoC, its architectural building block, and its applications along with the benefits.
SoC Architecture
A typical SoC architecture describes an integrated circuit which is incorporated with the below components.
- Processor
A device that fetches data from RAM, passes it, and pushes it back to RAM to complete a task. It is the heart of SoC and is configured with multiple co-processors. This co-processor can be anything ranging from DSP (Digital Signal Processing) to multiprocessor.
- Memory
The memory technologies embedded in SoC are Random Access Memory (RAM), Read Only Memory (ROM), and Electrically Erasable Programmable Read Only Memory (EEPROM). These memories in SoC are used for storage purposes. While RAM is a volatile memory that stores files being worked on temporarily, ROM is a non-volatile memory that stores instructions on the computer permanently. The job of EEPROM is to store bytes of data, erase it, and can be reprogrammed automatically.
- Graphical Processing Unit
GPU in SoC is used for interface visualization. It accelerates the graphical rendering and is same as CPU but with the difference that it deals with all the graphical aspects such as graphics, animation, etc.… on mobile devices or any other application.
- Digital Signal Processing
DSP, otherwise called Digital Signal Processing is used to drive digital signal processing tasks. The primary function of DSP in a chip is to perform data collection and processing. It is also used to decode images, audio, and speech signal processing, etc.…
- Peripheral Devices
A peripheral device can be an input device or an output device or a combination of both. There are several peripheral devices used in SoC such as the USB, Wi-Fi, Bluetooth, modems, etc.… which serve a different purpose according to the application in use.
- Encoders and Decoders
Encoders are used to convert the original data into a sequence of characters in a specialized format whereas decoders perform the reverse operation of converting the code into an original sequence of characters.
- Network Interface Card
A Network Interface Card, shortly known as NIC, is a hardware component that is used to connect over a network. It is usually a chip or a circuit board that is connected to the computer.
SoC Design Flow:
It takes both hardware and software to control the performance of the processor, DSP, and other memory units embedded in the SoC. This co-ordination of functionality is highly achieved through a robust flow. While the design process varies based on the requirements, let’s look at the standard design flow of System on a Chip.
The above figure shows the process flow of a top-down based traditional design structure as opposed to a platform-based design. While the former starts with the functional system requirement, the latter starts with building a platform for a given vertical space in an application.
In the top-down based approach, the first step in the design flow is the user requirements gathering which goes through various stages of refinement and is finally translated into a programming language such as C, C++. This is later pushed to the architecture design mapping where the hardware and software teams are grouped together, and the different algorithmic models are explored to best suit the design.
Different TLMs are explored at the next stage based on whether it’s timed or untimed. These Transaction Level Modelling approach help in modeling complex systems where it increases the level of design abstraction that’s happening above RTL (which is the next stage). RTL design is the critical step in any design workflow. Register Transfer Level is a methodology that focuses on defining the digital pieces of a system design.
IP cores are availed in different stages of the design cycle, and they are of different categories. Soft IP Cores are highly flexible and are used in the RTL stage for synthesizing the information from Hardware Description Language (HDL). Firm IP Cores on the other hand is done at the gate level and is delivered as a netlist. It is the combination of both hard and soft IP cores. Hard IP Cores, due to their complexity are implemented in fixed logic and cannot be removed or modified. These RTL designs can be in any hardware language such as Verilog or VHDL.
The next stage of design is referred to as ‘Synthesis’ which translates the implementation of logical gate into the targeted technology. This converts the. v format of RTL code into netlist which is of gate level. The next step in the process is combining these netlists into a schematic representation as a circuit which can later be printed on the chip. This is known as placing and routing of synthesized design into silicon which is then transferred for implementation. The final step in the process is ‘Validation’ which uses the typical functional testing performed during the system specification stage.
Where is SoC used?
SoC’s minimal space requirements and robust footprint have proven its efficiency in many areas of IoT. The System on a Chip is becoming quite popular in the areas of robotics, multimedia devices, and mobile devices. Other applications include as below:
- Automotives: The Advanced Driver Assistance System (ADAS), which is a suite of assistance features for safety and monitoring heavily relies on SoCs. Many automotivesystemsuse SoC for bundling various components involved such as GPS, Multimedia, and image processing technologies.
- Medical Equipment: Do you know that SoCs are extensively used in pacemakers which is used to deliver accurate electric simulation responses by monitoring the vital signs? There are also medical sensor devices which use SoCs to connect human body needs. Compact configuration is a key for achieving connected solutions in healthcare.
- Sensors: SoCs are widely used in sensors which are of varying types such as speedometers installed in vehicles, GPS location trackers and thermometer, etc.…
Other areas where the application of SoC is observed include smart home solutions, wearable devices, and much more.
Why SoC?
SoC has the smallest footprint with the highest economy of scale and its seamless functionality beats the traditional multi-chip architecture.
While SoC is known for increased productivity levels and decreased cost value along with lesser power, below are the key drivers of IoT movement towards SoC.
- Enhanced Connectivity – SoC provides seamless connectivity when integrated with multiple components. This paves the way for uninterrupted communication in IOT world.
- Easy Design – SoC is highly scalable and flexible which provides easy modification of different components within the SoC structure to meet different levels of design specifications.
- Reduction in Cycle Time – Since SoC execution is quite faster than others due to high-speed processors, there is an overall reduction in the cycle time of the system which leads to competitive performance levels. The power efficiencies are generally measured in performance per watt.