3 ms·

so, as someone naively excited about memristors I've noticed the similarity between Xpoint and memristive memory... am I totally off here though?

• wmf 9y ago
  XPoint is a form of chalcogenide resistive memory while HP memristors are titanium dioxide resistive memory.
  • shahar2k 9y ago
    is this a measure to avoid patent conflicts? (or is there an appreciable difference in inner workings)
    • brennanpeterson 9y ago
      Not a patent issue. PCM is also a NOR flash device, and have been used for decades in shipping memories. The answer to your paranthetical depends a bit on how much detail you care for. Both devices are types of resistive crosspoint memories. In XP, the resistor is a chalcogenide that has a low resistance polycrystal line state, and a high resistance amorphous state. These are tuned by the program pulse length. In TiO2, the mechanism is (presumably, perhaps debatebly) filamentary bridges between electrode, which can be eliminated by reversing the voltage. So on one level, both are resistive memories. On another, we are comparing a bulk phase transition driven by pulse control to a filamentary transition driven by voltage. Finally, the more important difference is the selector. PCM devices can use a chalcogenide based threshold switch. That is the OTS on the XP diagrams. That selector is the key to functional, dense memory arrays, and the existance of a matched selector is what makes PCM functional. I haven't seen what the matched selector for memristors is. Worth reading recent material from Crossbar on these topics.