Intel and ST Microelectronics have developed a technique to place multiple bits of data in a single memory cell in phase change memory. The technique effectively doubles the technology’s density.
Phase change memory is made of similar materials to CDs and DVDs. A laser rapidly heats up a small bit, transforming the bit’s structure from crystalline to amorphous.
Reversing the process can change the bit’s structure from amorphous back to crystalline again.
A light beam reflects off the bit, and its state, either amorphous or crystalline, is registered as a 1 or 0, the building blocks of data.
The Intel / ST Microelectronics partnership, a joint venture known as Numonyx, has developed an algorithm that can assign values to two additional intermediate states.
The companies are presenting a paper at the International Solid State Circuits Conference on a 256-megabit phase change chip that holds multiple data bits per cell.