Author: Peng Cheng
Industrial storage is a low-key yet critical niche market in the semiconductor industry. Unlike consumer-grade storage, which prioritizes capacity and cost, industrial storage focuses more on reliability, such as 24/7 continuous operation, wide-temperature environments from -40 to 125°C, strong vibration and electromagnetic interference, and frequent unexpected power outages. These operating conditions dictate that industrial equipment cannot directly adopt consumer-grade storage components, making "industrial-grade" a distinct product category separate from consumer and automotive grades.
Over the decades, industrial storage media have undergone several iterations but have never delivered a perfect answer that simultaneously meets all core requirements. It is not until MRAM technology has matured that the industrial storage medium seems to have found a "perfect answer" for the first time. As the only domestic manufacturer to achieve mass production of MRAM, HikStor Technology has built its own 12-inch production line and taken the lead in bringing this medium to industrial sites.
01. The Medium Dilemma of Industrial Storage
Looking back over the past thirty years, the choice of media for industrial storage has experienced several shifts, each replacement representing the elimination of the old medium by new demands.
Late 1970s and 1980s: The era of EPROM and EEPROM. Early industrial control computers relied on Erasable Programmable Read-Only Memory (EPROM) for program and parameter storage. EPROM required ultraviolet erasure and full-chip rewriting, making maintenance extremely inconvenient; EEPROM achieved electrical erasure and supported byte-level rewriting, offering much better maintainability than EPROM, but its endurance was only on the order of 10⁴ to 10⁵ cycles, with slow write speeds and limited capacity. Storage during this period solved the binary issue of whether "reprogrammability" existed or not, and it was far from addressing reliability metrics.
1990s: NOR Flash takes the baton. As flash memory processes matured, NOR Flash, with its low cost, fast read speeds, and well-established supply chain, quickly replaced EEPROM to become the mainstream for code and parameter storage in industrial control computers, a position it maintains to this day. However, it inherited the underlying limitations of EEPROM: an endurance of only 10⁵ cycles, leaving it inadequate for high-frequency data recording; the "erase-before-write" mechanism not only increased instruction and circuit complexity but also introduced data management risks with every write. This compromise is most evident in smart meters. For instance, metering and load profile data in electricity meters need to be written continuously at second-level intervals, which the lifespan of flash memory cannot sustain. Consequently, the industry developed a complex set of technical conventions: using software algorithms to "conserve" flash memory, designing redundant storage, and periodically migrating data. Engineers spent a massive amount of energy not on business logic, but on catering to the medium's lifespan.
The SRAM + battery/supercapacitor + Flash/EEPROM solution emerges. As the need for power-loss data retention in industrial equipment became clear, "the speed of SRAM + the retention capability of a battery" became the classic combination for power-loss data recording. However, power-loss retention relied entirely on the battery, requiring operators to conduct regular inspections and replacements; once a battery failed undetected, data would be lost. The most typical case is the PLC. As the core of industrial automation systems, PLCs generate process and result data in real-time during operation, imposing requirements for fast read/write speeds and endurance on the order of tens of billions of cycles on the memory, which exceeded the capabilities of conventional non-volatile memory at the time. Thus, SRAM + battery became the standard solution. Even today, many PLC motherboards still retain coin cell battery compartments.
Attempts at other parallel routes: NVRAM. The industry's exploration of Non-Volatile Random Access Memory (NVRAM) has never ceased, mainly involving three types of solutions: FRAM (Ferroelectric RAM), NVSRAM, and MRAM. Among them, FRAM boasts excellent endurance but is limited in capacity and relatively high in cost, making it difficult to handle medium-to-large capacity (above 4Mb) data recording; NVSRAM requires a supercapacitor to support data fallback after power loss and has limited capacity (no more than 4Mb) and high costs; MRAM requires no capacitors, offers sufficient endurance, and supports capacities at the 16Mb and 64Mb levels.
Returning to the essence, the storage requirements for industrial control computers can be summarized in four sentences: indestructible to writes, lossless on power drop, resilient to wide temperatures, and maintenance-free. The application of each generation of media solved a pain point of the previous one but left new shortcomings. No traditional route can simultaneously satisfy these four points; most solutions trade达标 (compliance) for "combinations" and "compromises".
02. High-Reliability Industrial Scenarios Push Storage Requirements to the Extreme
The shortcomings unresolved for forty years are particularly evident in high-reliability industrial scenarios. Industrial sites host a vast array of real-time control equipment that needs to save critical data such as device states and system logs in real-time and rapidly; industrial control equipment must also withstand harsh environments like high temperatures and vibrations; additionally, to avoid data loss caused by abnormal power drops, industrial control equipment typically requires backup batteries.
More severely, high-reliability industrial scenarios such as petrochemicals, power, and rail transit demand equipment lifespans of 15 to 20 years or more, making long-term maintenance-free operation a mandatory requirement; edge intelligent devices are often deployed in unattended or extremely high-maintenance-cost sites, where every component replacement translates into tangible O&M expenditures. Criticality and long lifespan push the requirements for industrial storage to the extreme.
The specific manifestations of these extreme requirements are: First, endurance reaching the order of 10¹⁴ (trillions) of cycles. In high-frequency recording scenarios, the 100,000-cycle endurance of traditional flash memory might be exhausted within months, causing the medium to fail before the equipment, an unacceptable failure mode in industrial sites. Second, non-volatility on power drop with data retention for over 20 years. Industrial equipment rarely shuts down after commissioning; data retention must be calculated in units of ten or twenty years; and this capability must not degrade with write/erase wear, which is precisely the Achilles' heel of all EEPROM/Flash-type devices. Third, write speeds sufficient to support safe data fallback in the instant of a power drop. True reliability is not "adding a battery as a backup," but ensuring that critical data has been written within the milliseconds of an unexpected power outage. This requires write cycles on the order of tens of nanoseconds, without relying on any backup components that require maintenance. Fourth, wide-temperature operating capability from -40 to 125°C. Site environments in rail transit, power, and metallurgy impose temperature range adaptability requirements on components far exceeding those of consumer-grade products. Fifth, capacity coverage capability. Edge intelligence is also increasing the volume of the critical data layer; operation logs have grown from a few Kb to several Mb or more, and fault recording requires recording minute-level or even hour-level waveform data. Reliable media must cover the complete range from Kb to hundreds of Mb. Although FRAM performs well, its capacity ceiling stops at the several-Mb level, leaving medium-to-large capacity needs unmet.
For individual metrics, traditional solutions can barely scrape by; but to achieve multiple metrics simultaneously, old technological routes are insoluble. NOR Flash fails on endurance and power-loss protection; SRAM + battery fails on maintenance-free operation and capacity; supercapacitors fail due to hidden failures; FRAM fails on the capacity ceiling. Industrial storage needs an evolution at the medium level.
03. MRAM: The "Re-Evolution" of Industrial Storage
MRAM (Magnetoresistive Random Access Memory) is a non-volatile magnetic random access memory that stores data using the magnetoresistive effect. Unlike traditional semiconductor Random Access Memory (RAM), MRAM uses Magnetic Tunnel Junctions (MTJ) as storage cells, recording binary data by changing the magnetization direction. This physical mechanism determines its innate endowments: the magnetic state is naturally retained after power-off, meaning inherent non-volatility; writing is accomplished by flipping the magnetization direction with current, offering read/write speeds close to SRAM; and it supports byte-level random addressing. In other words, MRAM inherently possesses both the speed of RAM and the non-volatility of Flash at the foundational level, being regarded as the realistic answer to "ideal storage."
From a parameter perspective, MRAM's metrics are exceptionally excellent. Specifically: an endurance of 10¹⁴ means it can be stably used for ten years even with millions of writes per second, completely eliminating lifespan anxiety in high-frequency recording scenarios; a high-speed write cycle of 35 ns allows critical data to be safely written in the instant of a power drop, requiring no capacitors and no batteries, eliminating the costs and hidden failure risks of regular maintenance from the source; byte-level addressing and no need to erase before writing simplify circuit and instruction design, making the entire data pathway more concise and reliable. Meanwhile, a product portfolio covering capacities from Kb to hundreds of Mb makes it the only solution among currently mass-produced NVRAMs for medium-to-large capacities (>4Mb). Parameter configuration areas, device log areas, and real-time data cache areas can all find corresponding implementation paths.
More importantly, MRAM is not停留在 (stuck at) the conceptual stage. Domestic manufacturer HikStor Technology has built its own 12-inch MRAM production line and is the only domestic manufacturer capable of providing mass-produced MRAM products. It has established 90nm, 40nm, and 28nm mass production platforms, offering standalone MRAM products and embedded IP customized development services. Currently, HikStor's MRAM has been deployed in industrial scenarios such as fault recording, high-frequency log recording, and wide-temperature data storage, providing a mass-production-verified storage foundation for high-reliability industrial control equipment.
By adopting the MRAM solution, the battery can be removed from the PLC. It is understood that the sampling frequency of PLC digital input modules is as high as500Hz. Calculated over a 20-year equipment lifespan, the cumulative write count reaches as high as 300 billion times, far exceeding the endurance of traditional non-volatile flash memory. HikStor's MRAM defuses three mines simultaneously with a single component: trillion-cycle endurance covers the entire lifecycle of writes, nanosecond-level writing ensures data fallback in the instant of a power drop, and the battery, a former point of failure, is eliminated from the solution. For the first time, PLC storage design can achieve maintenance-free operation throughout its entire lifecycle.
In terms of smart meters, the 2020 version of the smart electricity meter technical specification requires that the service life of the meter must not be less than 16 years. Calculated at a data saving frequency of 1 time/second,500 million metering data and load profile data entries need to be saved over 16 years. HikStor's MRAM, with its trillion-cycle endurance and nanosecond-level write speed, directly covers this requirement with component capability, without needing software to circumvent the insufficient read/write counts of traditional non-volatile memory.
04. The Next Stop for Industrial-Grade Storage
The evolution history of high-reliability storage in industrial scenarios is essentially a history of "using more reliable media to hedge against more stringent scenarios": from Flash to ferroelectric, from battery backups to capacitor buffering, every generation of solutions has been pushing the limits but has never simultaneously reached the endpoint of "indestructible to writes, lossless on power drop, wide temperature, and maintenance-free."
The emergence of MRAM allows this long journey of approximation to see the endpoint for the first time. For the domestic industrial industry, the significance goes beyond just a new component. In the current context where supply chain security is increasingly important, the completion of HikStor Technology's 12-inch MRAM mass production line means that the underlying capability for storage in high-reliability industrial scenarios has achieved localization for the first time. From components to ecosystem, the next stop for industrial-grade storage has already begun.