IoT memory: An overview of the options
The rapid development of the Internet of Things has created a number of exciting new opportunities and challenges for designers. However, one consideration cannot be overlooked: the need for the device to have memory. In this article, Cher Zevala compares memory options and revisits the IoT memory types.
The rapid development of the Internet of Things has created a number of exciting new opportunities and challenges for designers. Yet whether an IoT device is brand-new technology specifically designed to be connected, or an upgrade to an existing device to create more capability, there is one consideration that cannot be overlooked: The need for the device to have memory.
And while the number of memory options hasn’t quite reached the number of IoT devices on the market, when you are trying to make a decision about what to include, it can certainly feel that way. From traditional RAM-based and Flash memory to more advanced, chip-based memory solutions, there are plenty of options to choose from.
When comparing memory options, the first thing to determine is the device priorities. Depending on the device, you may need to consider:
Cost. Cost is a concern in any project; the more expensive the memory selection, the more expensive the final device. Depending on the market, you need to weigh the cost vs. performance options.
Size. Most IoT devices are small, and thus the embedded technology must also be small. The amount of space required for memory processing must also be kept to a minimum, as the more silicon wafer space required, the more costs go up.
Power Consumption. Most IoT devices either run on small batteries or rely on energy harvesting for recharging. For this reason, it’s important to consider the power consumption of the memory selection, and choose an option that uses the least amount of power and voltage, both in use and during standby.
Startup time. Users want excellent device performance, so memory needs to be sufficient to allow for a quick startup. Implementing a code-in-place option, which allows the device to execute code directly without needing to copy operating code from a separate EEPROM chip reduces the time required to boot up, as well as the cost of the chip since there is less need for RAM with substantial on-chip storage.
Keeping these points in mind will allow you to make the right memory selection for an IoT device. But what are the options you have to choose from?
Types of IoT memory
Typically, embedded technology engineers select memory from one of the following options.
Traditional External Flash Memory: Many consumer products use this type of memory, because it is inexpensive, reliable, and flexible, offering a high degree of density and the ability to execute in place without using too much power. Flash memory falls into two categories: NOR Flash and NAND Flash. NOR support execution in place (XIP), while NAND does not. NAND tends to be best suited for data heavy application, such as wearable devices, which require cheap, high-capacity storage, while NOR Flash is generally used for devices like GPS or e-readers that do not require as much memory.
Embedded Flash Memory: Embedded flash memory (also known as eFlash) is becoming more popular in IoT devices in which applications store critical data and code. Some experts predict that eFlash will become the most common type of IoT memory, given its high levels of performance and density, which allows it to support most microcontroller applications. This type of memory is also very flexible and can be programmed in the field.
Multichip Package Memory: Multichip-package (MCP) memory combines the CPU, GPU, memory, and flash storage in one chip. Currently, MCPs are common in smartphones and tablets, but they offer more power and more density for IoT devices. Engineers are currently developing MCPs that use less power but offer the same level of flexibility and computing ability.
Multi Media Cards. Embedded Multi Media Cards (eMMC) offer a great deal of storage for IoT devices, at a reasonable cost, with excellent performance and low power consumption. The cards use specifically designed controllers, allowing for better integration into application systems. In fact, eMMC’s performance is some of the most top rated, since it can process multiple tasks at once, effectively improving speed by up to 30 percent. The cards also offer a higher level of security, by expanding the common write-protect feature to prevent user data from being overwritten or erased without authorization.
Adding memory to an IoT device means making a number of important decisions, and identifying the best option. These are just a few of the viable options available to engineers, and more are in development. As the IoT continues to become a dominant force, expect to see even more high-quality, low-cost options on the market.