Paul A. Clayton (paaronclayton.delete@this.gmail.com) on November 19, 2018 5:08 pm wrote:
> David Kanter (dkanter.delete@this.realworldtech.com) on November 19, 2018 1:40 pm wrote:
> > Here's my second quick article from VLSI 2018. My first article focused on machine learning
> > accelerators, while this second article is on emerging memories - specifically MRAM.
>
> The technology might already be sufficiently mature to replace NOR flash in some microcontrollers
> (which use more mature process technologies both to get embedded flash and for cost
> reduction given I/O die size constraints). Execute-in-place, limited data logging and
> configuration storage would generally not require huge capacities.
>
> In some applications, persistence is a significant energy efficiency consideration. (Sadly, in my opinion, persistence
> does not mean non-destructive reads. Some applications can tolerate destructive (or disturbing) reads and could
> benefit from better density, but low-energy execute in place would seem more tolerant of lower density if it
> allowed non-destructive reads. Currently, MRAM appears to provide non-destructive reads, but I would not be
> surprised if that might be sacrificed in the future for greater density or other feature.)
>
> There probably are uses for small distributed persistent memories (perhaps localized, possibly more
> secure configuration storage?). If the lower density of small localized memories does not significantly
> impact chip-level density, there might be uses for such lower-density persistent memory.
>
> (For some applications, routing rather than a binary (variable strength) signal might
> be useful. If the orientation of an anti-fuse/phase change material could be controlled,
> such a "memory" might be used in FPGAs and perhaps some other areas.)
>
> Aerospace applications would also be concerned with radiation tolerance and magnetic field effects.
>
> [snip]
> > While MRAM is in production with Everspin, there is still a huge amount of research
> > around the basics. I hope to write an additional article about MRAM in the future,
> > since there are so many idiosyncracies around new memories.
>
> Idiosyncracies can be opportunities for optimization in application
> targeting, system hardware design, and software design.
>
> I am extremely ignorant in this area, but memory technologies do seem interesting.
>

MRAM is usually unstable at high temperatures iirc so puts a limit on the available market for MRAM in MCUs