* memristor memory will be a competitor to flash memory in three years that would have a capacity of 20 gigabytes a square centimeter.
* memristor memory will be faster and use less memory than phase-change memory. In Phase change memory, heat is used to shift a glassy material from an amorphous to a crystalline state and back.
* in the two years since announcing working devices, HP had increased memristor switching speed to match today’s conventional silicon transistors. The researchers had tested them in the laboratory, he added, proving they could reliably make hundreds of thousands of reads and writes.
HP thinks it can do even better and scale the technology to far lower process geometries than flash. The HP target is to double the density of flash in 2013 and have faster speed.
Flash density could be increased by upping the cell count in multi-layer cells (MLC). Two-bit flash is common now, three bit is coming and SanDisk has four-bit MLC patents. But flash write performance and endurance slows as more bits are added to cells, and flash controllers have to overcome this obstacle to make 3X and 4X MLC flash usable
In a paper in this week’s issue they describe using their memristor to perform several ‘stateful’ logic operations. In a nutshell, stateful logic means that the ‘state’ of the memristor acts as both the computer and the memory. That’s a pretty big change from current computers, which typically load data from memory, perform operations on it, and then send it back.
The authors of the International Technology Roadmap for Semiconductors1—the industry consensus set of goals established for advancing silicon integrated circuit technology—have challenged the computing research community to find new physical state variables (other than charge or voltage), new devices, and new architectures that offer memory and logic functions beyond those available with standard transistors. Recently, ultra-dense resistive memory arrays built from various two-terminal semiconductor or insulator thin film devices have been demonstrated. Among these, bipolar voltage-actuated switches have been identified as physical realizations of ‘memristors’ or memristive devices, combining the electrical properties of a memory element and a resistor. Such devices were first hypothesized by Chua in 1971 and are characterized by one or more state variables16 that define the resistance of the switch depending upon its voltage history. Here we show that this family of nonlinear dynamical memory devices can also be used for logic operations: we demonstrate that they can execute material implication (IMP), which is a fundamental Boolean logic operation on two variables p and q such that pIMPq is equivalent to (NOTp)ORq. Incorporated within an appropriate circuit memristive switches can thus perform ‘stateful’ logic operations for which the same devices serve simultaneously as gates (logic) and latches (memory) that use resistance instead of voltage or charge as the physical state variable.