Dec 12, 2013

Toshiba announced a new computing architecture that uses only STT-MRAM to perform both operations and storage. The idea support computing capability, register file, primary cache and secondary cache all on the same perpendicular STT-MRAM, and Toshiba says it could lead to CPUs that are drastically faster and more efficient.

Toshiba STT-MRAM storage and computing slide 2

Toshiba explains that in the new architecture, the results of operations (answers) that correspond to combinations of certain inputs are prepared in advance in the form of a table and stored in the memory. In response to an input, an answer is read out of the memory. This is equivalent to an operation carried out by a CPU. Because the computation answer is read once, it drastically improves processing speed and power consumption.

Toshiba STT-MRAM storage and computing slide 1

Toshiba did some simulations and they say that a division process that requires 50 processing cycles with a normal CPU requires only 16 cycles with the new architecture. In another example, 408 cycles usually required to solve a quadratic equation was reduced to just 44 cycles! The simulations used Toshiba's 1-Mbit array that uses the company's 2T-2MTJ structure.

The new method requires results of operations to be calculated in advance (on an "external computer") - this is basically just like today's computer which use compilers. STT-MRAM is suitable for this architecture because of its high-speed and non-volatility.