Local storage technologies for IoT devices

Data flood of the Internet of Things

Due to the unprecedented growth of Internet of Things (IoT) devices around the world, it has sparked the development of new technologies with a particular focus on storage. The devices that make up the Internet of Things are expected to generate ever larger amounts of data over the next few years. Developers need to determine where this data should be processed and stored. In addition to numerous online cloud storage solutions, local storage solutions are still required for use in IoT devices.

Local storage solutions

Due to its robust lifespan, local flash memories are extremely desirable in IoT applications that enable the storage of critical data and codes. Conventional flash memories are still used in IoT applications around GPS / navigation as well as in consumer products such as smartwatches due to their low cost, high storage density, operation in large temperature ranges and architecture. The storage technologies offer high flexibility and, above all, reliability.

NOR & NAND

NOR Flash is useful in applications that require code storage, such as Home gateways and set-top boxes are popular for their ability to support XIP applications and their low standby power consumption, while NAND is better suited for data storage applications that do not require XIP support. Data-intensive IoT applications like smart USB drivers and portable IoT devices require cheaper storage and use NAND flash because of its lower cost and higher storage capacity.

Characteristic	NAND Flash	NOR Flash
Cost per bit	Low	High
File storage use	Easy	Hard
Standby Power	High	Low
Active Power	Low	High
Read Speed	Low	High
Write Speed	High	Low
Capacity	High	Low
Code execution	Hard	Easy

eMMC storage

The IoT market is powered by low-cost devices that include sensors, gauges, robots, wearable devices, and consumer electronics products. EMMC storage is well suited for such applications because of its low cost and its ability to act as a replacement for traditional storage media. The eMMC standard was developed to simplify the design of the application interface by moving the flash controller that interacts with the flash memory in the memory itself. The simpler design benefits IoT storage developers by reducing the space required for storage devices and thereby lowering costs. The eMMC 5.1 specification enables fast transfer speeds of up to 400 MB / s and capacities of up to 128 GB.

UFS storage

eMMC faces high competition from UFS 2.0, which offers higher data transfer speeds and lower power consumption than eMMC and is often viewed as the successor to the eMMC standard. Both embedded and removable flash memory are expected to operate in IoT devices. The evolution from eMMC to UFS offers advantages in terms of performance and low power consumption. On the performance side, it offers 600 MB / s compared to 200 MB / s for eMMC, while on the performance side it offers a performance reduction of 30% to 55%. The higher performance of UFS is also the result of architectural changes in the link layer. UFS has serial and full-duplex connection, while eMMC has parallel and half-duplex interfaces, which blocked higher-speed operation and efficient execution of commands.

What does the future of storage solutions for IoT devices look like?

IoT applications will continue to drive the development of various storage technologies, with each type of application having unique requirements. It is clear, however, that cost and power will be a challenge as most of the expansion of the IoT market is being driven by portable devices, driving embedded NVM and external NVM towards future growth.