Micron NOR, NAND Flash
Selecting a flash memory solution for embedded applications
When looking for flash memory for your embedded applications, Micron has the right solution. Our many years of embedded industry experience and our broad portfolio of NOR and NAND flash memory products – from serial, octal and parallel NOR flash, to raw and managed NAND flash, to SSDs – provide you with ideal code and data storage solutions. Selecting the right solution requires an understanding of each technology, including attributes related to 1/0 performance, pin count, data integrity, and manufacturing longevity requirements. This guide describes the various flash technologies and provides a systematic way for embedded system designers to select the optimal nonvolatile memory solution based on key design considerations. Application requirements will ultimately dictate the right solution.
Getting to know NOR Flash
NOR flash devices, available in densities from 128Mb up to 2Gb, are primarily used for reliable code storage (boot, application, OS, and execute-in-place [XIP] code in an embedded system) and frequently changing small data storage. NOR flash provides systems with the fastest bootable memory solution for instant on performance, is easy to implement, and requires minimal ongoing management due to the underlying cell structure. Because of the cell structure, NOR flash is inherently more reliable than other solutions. NOR low pin counts and small package solutions make it a good fit for applications like automotive ADAS (advanced driver-assist systems) and IVI (in-vehicle
infotainment), IPC/factory automation, intelligent edge devices, machine-to-machine, healthcare, radio access networks (RAN), servers and routers, wearables, cameras, and printers. Octal flash leverages the best of serial NOR flash and parallel NOR flash to offer system designers both high performance and low pin counts. Serial NOR flash, with its high-speed continuous read capabilities throughout the entire memory array and its small erase block sizes, is tailored for applications that shadow program code and/or store granular data. Parallel NOR flash provides direct memory access and fast random-access reads for legacy interfaces that continue to be widely adopted.
Getting to know NAND Flash
NAND flash devices, available in 128Mb to 2Tb+ densities, are used to store data and code. Low-density NAND flash is ideal for applications like automotive, surveillance, machine-to-machine (M2M), IPC, automation, printers and home networking while high-density NAND flash is most commonly used in data-heavy applications like SSDs, tablets, and USB drives. There is a continuous effort to reduce the cost/GB of NAND devices, so device lifecycles tend to be shorter with more frequent process lithography shrinks than NOR flash. NAND requires a controller, either internal or external, and specific firmware for error code correction (ECC), bad block management, and wear leveling. There are two primary types of NAND: raw and managed. Raw NAND comes in different flavors, including single-level cell (SLC), multi-level cell| (MLC), triple-level cell (TLC) and quad-level cell (QLC). Additionally, NAND technology is migrating from planar to 3D for higher density applications. 3D NAND has an inherently larger cell, so TLC based on 3D (3D-TLC) is expected to become mainstream in the next 1-2 years. Raw NAND requires external management but is the lowest cost/GB NAND flash available. Managed NAND incorporates memory management into the package, simplifying the design-in process.
NOR and NAND features comparison
Xccela Octal Flash, Serial NOR, Parallel NOR
- Lower density
- Low pin count (Octal and Serial)
- Ease-of-use
- Reliable code and data storage
- Fast read and random access times
- Higher endurance and data retention
SLC/MLC/TLC/SPI NAND, Managed NAND
- Higher density, low pin count
- Requires controller management (SLC, MLC)
- Mostly data-focused
- Fast writes and erases
- Focused on highest reliability and performance (SLC), optimum reliability and lower cost (MLC and 3D TLC), cost-focused applications (QLC), and reduced time-to- market/ease of design-in with managed NAND
Other design considerations include controller type, voltage requirements, individual parameter and feature specifications, security*, and software.
Densities offered by device type
The chart below shows various NOR and NAND density ranges to help identify the best solution for your application requirements.
NOR and NAND read performance
As shown in the figure below, read performance is mostly governed by bus width and clock speed (e.g., x16 and 133 MHz).
Micron NOR Flash portfolio Xccela™ Octal Flash
Octal flash memory offers the highest performance, lowest pin count (only 11 active signal pins) and lowest energy consumption compared to other NOR flash solutions. Xccela Octal flash memory leverages the JEDEC compatible SPI interface to deliver breakthrough performance. In addition to enabling one of the fastest possible direct code execution and code shadowing, Xccela Octal flash paves the way for simpler system designs, lower system costs, and lower energy consumption.
Serial NOR
Due to its interface and low pin count, Micron’s serial NOR flash is an easy-to-use solution for applications that code shadow; simply provide a starting address in the memory to read and then continuously clock data out from the device throughout the entire memory array. Advanced security and memory protection features, including RPMC (replay protected monotonic counter) provide peace of mind for securing vital program code and sensitive user data*. Micron’s twin-quad serial NOR flash combines two quad 1/0 devices into a single package to create an 8-bit, bidirectional I/O structure, which effectively doubles the bandwidth and performance while maintaining the same footprint as a serial NOR flash.
Parallel NOR
Parallel NOR flash devices operate in page mode for use in applications where code runs directly from the device. This minimizes system boot time, making it ideal for process intensive applications that need performance. Parallel NOR devices also provide data security options* and feature expanded 1.65-3V I/0 (VCCQ) voltage. Parallel NOR is offered in choice of standard packages.
‘Not all densities available in all package and voltage combinations. Some densities offered as stacked solutions.
Micron NAND Flash portfolio
Select from one of the industry’s broadest portfolios of raw and managed NAND flash. To meet the high reliability and temperature requirements of embedded applications like automotive and industrial, many of Micron’s NAND flash solutions are ISO/TS 16949-certified and have extended temperature ranges as well as long product lifecycles.
Raw NAND
Raw NAND provides the lowest cost per bit but requires an external host controller (not contained within the package) to perform all management functions (e.g., ECC, FTL).
- Single-level cell (SLC)
One bit per cell; high performance and write endurance and lowest cost/bit for ≤1GB densities. Low-density SLC is used for code storage in embedded applications while high-density SLC is used in mission-critical systems where high performance and best-in-class reliability are required. - Serial SLC NAND
Low-density SLC devices with a NOR-like serial interface simplify system design. - Triple-level cell (TLC)
Three bits per cell; high cell density, but lower performance and endurance specifications. Most often used in mass storage consumer applications (client SSDs, USB drives, SD cards) with very high cost sensitivity; however, with 3D TLC NAND, reliability is adequate for applications that use planar MLC. - Quad-level cell (QLC)
Four bits per cell; higher density and larger capacity at lower cost per bit; lower endurance and slower speed compared to TLC NAND; suitable for read-intensive applications. - On-Die ECC NAND
Hybrid between raw and fully managed NAND; ECC is integrated while wear leveling and bad block management are handled by the host controller.
Managed NAND
Managed NAND provides simpler solutions and accelerates time-to-market because the controller is embedded within the package to handle wear leveling, bad block management, and ECC. - e.MMC/UFS memory
High-capacity NAND flash device combined with a high-speed multi-media card (MMC) controller in a single BGA package; suitable for designers looking for a fully managed device and ease of design for MMC-like, application-to-application interoperability for a wide range of networking, industrial, and automotive applications. - Solid State Drives (SSDs)
NAND-based PCle and SATA SSDs enhance reliability, reduce power, and provide faster performance compared to hard disk drives (HDDs). - microSD Card
Advanced Micron 3D NAND flash memory technology-based removable storage devices are specifically designed to meet the performance, capacity and quality required for industrial devices and systems.
Selecting a NAND device
Use the following tables to help select the right NAND device to match your design requirements. For more details, see our NAND part catalogs and our Choosing the Right NAND page, or find a sales representative at micron.com.
Benefits of partnering with an embedded memory expert
As a leading supplier of memory for 30+ years with an in-depth understanding of the embedded industry, you can rely on Micron as a single source for your embedded memory needs. Team up with us for:
Unwavering commitment
Micron is expanding its Manassas, U.S. fabrication site to support the rapidly growing need for high-quality, high-reliability memory solutions. This site manufacturers our long-lifecycle products to ensure supply continuity for the industrial and automotive markets. Delivering a leading-edge, state-of-the-art auto- and industrial-qualified memory portfolio with associated lifecycle support places Micron in a class by itself and further underscores our continued commitment to these markets.
The tools to enable your next-generation innovation
Get the right memory technology-designed for embedded industry requirements just the right time thanks to our ever-expanding industry knowledge base and strong relationships with chipset vendors. Coupled with support from our embedded memory experts and technical resources, you’ll be armed with a total solution that is optimized for your next-generation embedded applications.
Reliability from a world-class supplier
Rely on products that are manufactured by Micron with a focus on high quality and reliability standards. We test select devices with an extended temperature range of -40°C up to 125°C for the highest reliability, and many of our products have also achieved ISO/TS certification. As new designs emerge and requirements shift, you can continue to depend on Micron to offer the broadest portfolio of memory solutions to fuel your embedded innovations. Learn More: for more about Micron’s flash memory solutions, or to find a sales representative or authorized distributor, go to micron.com.
*No hardware, software or system can provide absolute security under all conditions. Micron assumes no liability for lost, stolen or corrupted data arising from the use of any Micron products, including those products that incorporate any of the mentioned security features. Products are warranted only to meet Micron’s production data sheet reis etty chan Micith tenotice Dates estimates other Micro trade march are the prol rights Micron Technology, Inc. All other trademarks are the property of their respective owners.
FAQ
- What are the key considerations when selecting between NOR and NAND flash?
- Consider factors like application requirements, performance needs, data retention, reliability, cost, and design complexity when choosing between NOR and NAND flash solutions.
- How does Xccela Octal Flash differ from Serial and Parallel NOR flash?
- Xccela Octal Flash combines the best of both serial and parallel NOR flash technologies, offering high performance with low pin counts for system designers.
Documents / Resources
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Micron NOR, NAND Flash [pdf] Instructions NOR NAND Flash, NOR Flash, NAND Flash, Flash, NOR NAND, NOR, NAND |