The next generation
of NonVolatile RAMs (NVRAM)
Today's only popular non volatile memory is flash memory.
Though the market is growing very well for this non-volatile
early bird, it has got it's own set of problems in replacing
either Hard-disk or DRAMs completely. The long access time
of milli seconds and limited life span of less than 100,000
write cycles are the main complaints of this memory.
Many leading semiconductor companies (Intel, Samsung, IBM,
Freescale, TI, RAMTRON, and many more) are developing alternative
technologies to flash and get rid of the entire drawback the
flash has. Here in this article, we briefly touch upon the
technology and give some basic idea of each NVRAM concepts.
Here we go by the order of their commercialization.
FRAM (Ferro Random Access Memory): Ramtron has pioneered
in commercializing this technology. FRAM is already available
in huge production quantities. You can also source 8051 based
microcontroller's integrated with FRAM. The speed and life
is very good compared to Flash. However the maximum capacity
available is uncomparable to flash.You hardly get 1MB in a
The technology is based on DRAM itself. In DRAM the capacitor
stores the charge but need to be refreshed due to capacitor's
leakage, say you replace the capacitor with a ferro-electric
material called Lead Zirconate Titanate (PZT) so that the
charge stays there even without power, than it is FRAM.
In the present scenario there are few applications where
FRAM can perform far better than Flash. The long term future
of FRAM can be positive if the size increases and cost per
MRAM (Magnetoresistive Random Access Memory): Freescale is
the company which is sitting pretty well on this technology
and also launched 4M bit chip in 2006. It is yet to know how
market is responding to this new chip. If the technology is
compared to DRAM and flash, all the key factors shows, this
can become future NVRAM. It all depends on how fast the cost
per MB falls close to flash and sizes of giga-byte are released
at the earliest.
This technology is also similar to DRAM. The key storage element
is a set of two magnetic plates. One plate is permanent magnet
and other is magnetically charged to high or low.
It's as fast as SRAM and also can scale down to store huge
capacities and read/write cycles written can be infinite.
PRAM (Phase change Random Access Memory): Samsung has demonstrated
prototype of 256 MB PRAM in Sept 06. Along with the benefits
of what MRAM offers over flash, PRAM also has size advantage.
We can expect the working model of 512MB capacity from Samsung
after once it's commercialized.
The problem with PRAM is, the technology is still in experimental
stage. We can only confirm it's lead over flash and other
NVRAMs only when the production volumes are announced. However
it can be suggested to seriously watch this technology for
potential replacement of flash.
Other NVRAM technologies: The world is waiting for nano technology
to produce MOSFETS and other storage devices at nano scales.
There are many papers getting published and serious research
is going on in every hi-tech institutes around world on nano
technology. One name popping up is Nano RAM; made using nanotubes.
Once we see new memory or processor devices from nano-technology
all the present technologies will be dropped like how old
vaccum tube technology is dropped. Nothing can be predicted
on this at this stage except there will be some pleasant shock
in near future.