Dialog’s New SPI NOR Flash: The Holy Grail of Low-power Memory?

Releasing within the second quarter of 2021, Dialog Semiconductor has developed new serial NOR 1 Mbit and a couple of Mbit Flash reminiscence configurations, which for power-conscious and space-constrained units.


Dialog’s New SPI NOR Flash: The Holy Grail of Low-power Memory?

The brand new AT25EU NOR Flash is designed for low-power IoT units.  Picture used courtesy of


As typical, when a tool is claiming the bottom energy and power within the trade, it’s essential to look deeper and analyze if this system can again up its claims. Earlier than that, although, it could be helpful to evaluation the serial protocol SPI and the way serial Flash compares with parallel Flash.


A Fast Evaluate of SPI

is a 4-wire communications protocol generally utilized in many chip-to-chip purposes. Three indicators, together with CLK, MOSI, and MISO, are shared between the shopper system and the server units. (Creator’s observe: You might even see these phrases known as “grasp/slave” units, although using these phrases is ).

The ultimate wire, chip choose, is exclusive to every server system.


Dialog’s New SPI NOR Flash: The Holy Grail of Low-power Memory?

A diagram of a number of slave choose. Picture used courtesy of


SPI is used continuously for designs that require full-duplex communication between shopper and server by shifting one bit in every course throughout every clock interval.

Since NOR Flash is commonly learn as configuration information earlier than loading into energetic reminiscence, what efficiency profit does serial flash provide in comparison with parallel bus schemes?


Can SPI Exchange The Parallel Bus for NOR Flash?

In contrast to the I2C normal, which SPI has no actual standardization related to its protocol.

One method to apply this profit is through the use of high-speed clocks to multiply throughput. By rising the clock pace and lowering the required variety of traces within the PCB floor space the space-constrained embedded system might be optimized.


Dialog’s New SPI NOR Flash: The Holy Grail of Low-power Memory?

Floor space comparability between Serial vs. Parallel NOR Flash on a PCB. Picture used courtesy of


The SPI baud charges differ from vendor to vendor and This skill makes it potential to compete with parallel NOR Flash in efficiency, particularly as soon as factoring in different design concerns.


What Design Considers Exist Between SPI & Parallel NOR?

Embedded designs are, by definition, low energy, and sometimes run on battery energy. A fast search at your electronics vendor of alternative will reveal a slightly vital tradeoff between parallel and serial flash units when it comes to energy consumption.

For instance, the from Microchip Know-how is a 2 Mbit parallel NOR flash working at 3V0/20 mA (max), as in comparison with

Past energy, there may be additionally a quest to scale back the scale and value of IoT units. Parallel NOR would require a extra complicated PCB, each for breakout house on the board and matching the timing constraints between traces.

Now that the variations between SPI and parallel NOR have been thought-about, one other comparability is serial NOR versus serial NOR.


How Does Dialog Semiconductors’ AT25EU Stackup to Competitors?

The datasheet for the just isn’t freely accessible but; nonetheless, primarily based on the launched particulars, plainly the AT25EU presents a deep power-down mode of 100 nA.

To create a comparability, one other serial NOR to take a look at is the 2 Mbit Serial NOR from Macronix, which presents an equivalent voltage working vary because the AT25EU, nonetheless, it additionally has a deep-down energy requirement of 70 nA to 350 nA.

From this particular comparability, it turns into obvious that the race for the bottom energy SPI NOR Flash is a decent one.


Dialog’s New SPI NOR Flash: The Holy Grail of Low-power Memory?

Instance AT25EU energy requirement metrics. Picture (modified) used courtesy of


Contemplating the goal marketplace for this chip, complete power utilized (energy multiplied with time) is one other metric that Dialog Semiconductor highlights as aggressive with this system. The AT25EU additionally claims to carry out a full erase in 10 ms (evaluate with a full erase of two.7 to eight seconds for the MX25R2035F), which might be helpful.

Although this product seems to be holding up its claims, Dialog Semiconductor additionally has quite a lot of reminiscence choices accessible, together with options for NXP’s i.MX and STMicroelectronics microcontroller households, which, relying on the appliance and venture, may add additional advantages.