Betty Prince and David Prince
Memory Strategies International
Texas, USA
This edition first published 2018
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Library of Congress Cataloging‐in‐Publication Data
Names: Prince, Betty, author. | Prince, David, 1966– author.
Title: Memories for the intelligent internet of things / by Dr. Betty Prince, David Prince.
Description: Hoboken, NJ : John Wiley & Sons, 2018. | Includes bibliographical references and index. | Descr
Identifiers: LCCN 2018001009 (print) | LCCN 2018012072 (ebook) | ISBN 9781119296409 (pdf) | ISBN 9781119298953 (epub) | ISBN 9781119296355 (cloth)
Subjects: LCSH: Computer storage devices. | Internet of things.
Classification: LCC TK7895.M4 (ebook) | LCC TK7895.M4 P735 2018 (print) | DDC 004.67/8–dc23
LC record available at https://lccn.loc.gov/2018001009
Cover Design: Wiley
Cover Image: Images courtesy of Betty and David Prince
background: © flowerstock/Shutterstock
The Internet of Things (IoT) has evolved from an older concept of Machine to Machine communications composed of specialized networks of things sending and receiving data obtained from the environment without the necessity of human intervention. The “Internet of Things” (IoT) is a concept of everyday objects that have network connectivity and can send, receive, and analyze data. An “Intelligent Internet of Things” will send, receive, and analyze data as well as have the capability to act with an intervention resulting from the analysis. Individual specialized networks are expected to communicate their knowledge to other networks to improve the function of a web of networks extending over the span of human existence.
These networks are everywhere. In retail stores, early bar codes provided scanned knowledge of inventory, its price, and some recorded indication of its origin. Bar codes have been replaced in high end retail stores with RFID tags, which can provide information on the state of the merchandise. For example, temperature monitors on wine bottles can detect temperature and record information on the maximum temperature experienced. This information can be radioed from the tag to a nearby receiver, which can analyze the state of the inventory and make recommendations on pricing or returns. These can then be recorded on the original RFID tag.
There are other examples of intelligent networks of systems communicating with each other. Wearable medical devices can take data and transmit it regularly to the medical provider node, which aids in medical monitoring and evaluation of patients. It also can implement relevant medical practices, in response to the original input, by feeding the recommended treatment back to the wearable devices. The outcome of the treatment could be collected with similar data to rapidly evolve successful new treatments.
Networks in smart homes are another example. Sensors can detect motion, fire, smoke, state of door locks; control cameras or audio devices record this information and turn on/off household equipment under the guidance of a smart network controller. An intelligent house network can turn on the installed sprinkler system as a result of rising temperature or fumes, which indicate a fire, along with setting off the fire alarm, notifying the fire department, and alerting first responders to the presence and location of people in the structure. Networks in traffic management systems in “Smart Cities” use embedded intelligence to control traffic lights to improve the flow of traffic, which could be detected from sensors along the curb set to register automobile location and detect speed. These sensors could also flag traffic monitors if excess speed is detected. The Smart City as a web of interacting networks supporting human existence is discussed in Chapter 1.
The MCU requirements for the various IoT applications differ significantly and affect the type of embedded nonvolatile memory that can be used in the MCU for that application. Embedded memory considerations include: standby power, active power, endurance, program and erase voltage, read and write speed, and data retention. These depend on the particular application the MCU will be used in. There are also options for the types of embedded memory technology to use.
Applications of interest include: ultralow power MCU used with energy harvesting and those used with battery operated applications, processors with nonvolatile arrays and power gating, processors used in intermittent operations, and communications processors. Processors used in automotive network applications have a different set of requirements for embedded memory. The varying characteristics of different IoT applications for processors and their embedded memories are discussed in Chapter 2.
For IoT processors to be made at low cost and in high volume, the memory in these processors needs to be manufacturable in high volume on standard CMOS logic processing lines. Currently most wafer fabrication areas have simple conventional embedded Flash memory and EEPROM macros available to be used as IP in MCUs run on their processing lines. As the demand for IoT processors has risen, new configurations of these well understood logic compatible memories have been developed. Chapter 3 discusses the status and development of embedded floating gate Flash and EEPROM memory as well as charge trapping memories that are CMOS logic compatible.
The requirements for both memories and processors in battery powered or energy harvesting sensors are very low power and very low cost. For wearable devices, the circuitry must be flexible. Circuits that can be made in large volume without the expense of semiconductor processing might lower the cost so a significant amount of effort has gone into ferroelectric, charge trapping, and resistance memories that can be made by inkjet printing or screen printing and can also form logic circuits. Chapter 4 discusses the evolution of these efforts to produce low power, low cost, flexible memories for the Internet of Things. It also discusses flexible circuits with higher performance made from thinned silicon chips mounted on a flexible substrate.
Local area networks (LANs) on the edge of the Internet can potentially use the memory‐based neuromorphic computers that are currently reaching an early level of capability. The use of these local intelligent nodes mean that local data can be analyzed and the results sent to the Cloud. This can provide an extra level of data security. The development of these memory‐based neuromorphic computers is discussed in Chapter 5.
The significant amount of data that is collected by the many sensor nodes and the identification data of these nodes must be stored where it is widely available, generally in the banks of servers that make up the Internet Cloud. The memory hierarchies in these servers are critical for the efficient functioning of the system. Sophisticated search engines associated with the Cloud servers need a new level of artificial intelligence that is currently under development. A few such artificial intelligence systems are discussed in Chapter 6.
Chapter 7 discusses various aspects of Internet Security involving memory devices. The use of physical unclonable functions (PUF) based in emerging memory devices such as MRAMs and RRAMs is also covered here.