US spies' crazytech branch asks chip firm for 8-BIT-PER-CELL memory

The blue-sky researchers who work for the US intelligence branch have handed a contract to magnetic semiconductor firm Crocus Technology to develop memory that stores a whopping 8-bit-per cell memory to help keep the United States' intel secure.

IARPA, the US Intelligence Advanced Research Projects Activity, has commissioned Crocus to deliver a working demonstration of the tech by the end of the year. Crocus says its Magnetic Logic Unit (MLU) memory "vastly exceeds" the current limit of the number of bits that can be stored per memory cell and will make it hellishly difficult to hack secret cryptographic keys stored in such memory. Crocus is in the business of making embedded micro-controllers for the mobile and security industry, as in smartcards, and also for applications requiring extreme operation conditions.

Crocus' multi-bit technology is going to use two magnetic structures:

• The Axial Induced Moment (AIM) uses a variable angle magnetic moment vector to encode binary data in a magnetic cell. It reckons it can demonstrate AIM with 16 storage angles yielding 4-bits per AIM cell; halfway there.
• The Multi-Junction Magnetic Tunnel Junction (MJM) which has two tunnel barriers stacked in a single MLU cell. HAve an AIM per tunnel barrier and we get to 8-bits.

There will be a combined AIM/MJM structure, in which the two MJM storage layers each support a rotating AIM storage vector, giving us 16 states in each of two independent storage layers, "resulting in 256 possible stored states or 8-bits per cell storage density" according to the Crocus bods.

Douglas Lee, VP for system strategy and corporate product development at Crocus, pointed out NAND and MRAM bits-per-cell limitations: "The current semiconductor non-volatile memory state-of-the-art is 3-4 bits per cell, as achieved in NAND flash memory, and is reaching the physical limits of floating gate memory technology. The current state-of-the-art in MRAM is only 1 bit per cell storage."

The contract will run for a year and result in 8-bit MLU memory being demonstrated in 12 months' time. Whether there is scope for such cell multi-bittery to cross over into more mainstream memory technologies is a moot point.

Likely not, although Crocus and IBM have been working on MRAM. ®