Tapa (tapabrata_ghosh.delete@this.vathys.ai) on November 19, 2018 10:06 pm wrote:
> 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

What do you mean by high temp? I know it can survive solder reflow (or so GF claims), which is >200C I think. Not sure if you want to operate at those temps.

David